• Title/Summary/Keyword: Network traffic test

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Video Streaming Receiver with Token Bucket Automatic Parameter Setting Scheme by Video Information File needing Successful Acknowledge Character (성공적인 확인응답이 필요한 비디오 정보 파일에 의한 토큰버킷 자동 파라메타 설정 기법을 가진 비디오 스트리밍 수신기)

  • Lee, Hyun-no;Kim, Dong-hoi;Nam, Boo-hee;Park, Seung-young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.10
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    • pp.1976-1985
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    • 2015
  • The amount of packets in palyout buffer of video streaming receiver can be changed by network condition, and saturated and exhausted by the delay and jitter. Especially, if the amount of incoming video traffic exceeds the maximum allowed playout buffer, buffer overflow problem can be generated. It makes the deterioration of video image and the discontinuity of playout by skip phenomenon. Also, if the incoming packets are delayed by network confusion, the stop phenomenon of video image is made by buffering due to buffer underflow problem. To solve these problems, this paper proposes the video streaming receiver with token bucket scheme which automatically establishes the important parameters like token generation rate r and bucket maximum capacity c adapting to the pattern of video packets. The simulation results using network simulator-2 (NS-2) and joint scalable video model (JSVM) show that the proposed token bucket scheme with automatic establishment parameter provides better performance than the existing token bucket scheme with manual establishment parameter in terms of the generation number of overflow and underflow, packer loss rate, and peak signal to noise ratio (PSNR) in three test video sequences.

DEVELOPMENT OF STATEWIDE TRUCK TRAFFIC FORECASTING METHOD BY USING LIMITED O-D SURVEY DATA (한정된 O-D조사자료를 이용한 주 전체의 트럭교통예측방법 개발)

  • 박만배
    • Proceedings of the KOR-KST Conference
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    • 1995.02a
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    • pp.101-113
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    • 1995
  • The objective of this research is to test the feasibility of developing a statewide truck traffic forecasting methodology for Wisconsin by using Origin-Destination surveys, traffic counts, classification counts, and other data that are routinely collected by the Wisconsin Department of Transportation (WisDOT). Development of a feasible model will permit estimation of future truck traffic for every major link in the network. This will provide the basis for improved estimation of future pavement deterioration. Pavement damage rises exponentially as axle weight increases, and trucks are responsible for most of the traffic-induced damage to pavement. Consequently, forecasts of truck traffic are critical to pavement management systems. The pavement Management Decision Supporting System (PMDSS) prepared by WisDOT in May 1990 combines pavement inventory and performance data with a knowledge base consisting of rules for evaluation, problem identification and rehabilitation recommendation. Without a r.easonable truck traffic forecasting methodology, PMDSS is not able to project pavement performance trends in order to make assessment and recommendations in the future years. However, none of WisDOT's existing forecasting methodologies has been designed specifically for predicting truck movements on a statewide highway network. For this research, the Origin-Destination survey data avaiiable from WisDOT, including two stateline areas, one county, and five cities, are analyzed and the zone-to'||'&'||'not;zone truck trip tables are developed. The resulting Origin-Destination Trip Length Frequency (00 TLF) distributions by trip type are applied to the Gravity Model (GM) for comparison with comparable TLFs from the GM. The gravity model is calibrated to obtain friction factor curves for the three trip types, Internal-Internal (I-I), Internal-External (I-E), and External-External (E-E). ~oth "macro-scale" calibration and "micro-scale" calibration are performed. The comparison of the statewide GM TLF with the 00 TLF for the macro-scale calibration does not provide suitable results because the available 00 survey data do not represent an unbiased sample of statewide truck trips. For the "micro-scale" calibration, "partial" GM trip tables that correspond to the 00 survey trip tables are extracted from the full statewide GM trip table. These "partial" GM trip tables are then merged and a partial GM TLF is created. The GM friction factor curves are adjusted until the partial GM TLF matches the 00 TLF. Three friction factor curves, one for each trip type, resulting from the micro-scale calibration produce a reasonable GM truck trip model. A key methodological issue for GM. calibration involves the use of multiple friction factor curves versus a single friction factor curve for each trip type in order to estimate truck trips with reasonable accuracy. A single friction factor curve for each of the three trip types was found to reproduce the 00 TLFs from the calibration data base. Given the very limited trip generation data available for this research, additional refinement of the gravity model using multiple mction factor curves for each trip type was not warranted. In the traditional urban transportation planning studies, the zonal trip productions and attractions and region-wide OD TLFs are available. However, for this research, the information available for the development .of the GM model is limited to Ground Counts (GC) and a limited set ofOD TLFs. The GM is calibrated using the limited OD data, but the OD data are not adequate to obtain good estimates of truck trip productions and attractions .. Consequently, zonal productions and attractions are estimated using zonal population as a first approximation. Then, Selected Link based (SELINK) analyses are used to adjust the productions and attractions and possibly recalibrate the GM. The SELINK adjustment process involves identifying the origins and destinations of all truck trips that are assigned to a specified "selected link" as the result of a standard traffic assignment. A link adjustment factor is computed as the ratio of the actual volume for the link (ground count) to the total assigned volume. This link adjustment factor is then applied to all of the origin and destination zones of the trips using that "selected link". Selected link based analyses are conducted by using both 16 selected links and 32 selected links. The result of SELINK analysis by u~ing 32 selected links provides the least %RMSE in the screenline volume analysis. In addition, the stability of the GM truck estimating model is preserved by using 32 selected links with three SELINK adjustments, that is, the GM remains calibrated despite substantial changes in the input productions and attractions. The coverage of zones provided by 32 selected links is satisfactory. Increasing the number of repetitions beyond four is not reasonable because the stability of GM model in reproducing the OD TLF reaches its limits. The total volume of truck traffic captured by 32 selected links is 107% of total trip productions. But more importantly, ~ELINK adjustment factors for all of the zones can be computed. Evaluation of the travel demand model resulting from the SELINK adjustments is conducted by using screenline volume analysis, functional class and route specific volume analysis, area specific volume analysis, production and attraction analysis, and Vehicle Miles of Travel (VMT) analysis. Screenline volume analysis by using four screenlines with 28 check points are used for evaluation of the adequacy of the overall model. The total trucks crossing the screenlines are compared to the ground count totals. L V/GC ratios of 0.958 by using 32 selected links and 1.001 by using 16 selected links are obtained. The %RM:SE for the four screenlines is inversely proportional to the average ground count totals by screenline .. The magnitude of %RM:SE for the four screenlines resulting from the fourth and last GM run by using 32 and 16 selected links is 22% and 31 % respectively. These results are similar to the overall %RMSE achieved for the 32 and 16 selected links themselves of 19% and 33% respectively. This implies that the SELINICanalysis results are reasonable for all sections of the state.Functional class and route specific volume analysis is possible by using the available 154 classification count check points. The truck traffic crossing the Interstate highways (ISH) with 37 check points, the US highways (USH) with 50 check points, and the State highways (STH) with 67 check points is compared to the actual ground count totals. The magnitude of the overall link volume to ground count ratio by route does not provide any specific pattern of over or underestimate. However, the %R11SE for the ISH shows the least value while that for the STH shows the largest value. This pattern is consistent with the screenline analysis and the overall relationship between %RMSE and ground count volume groups. Area specific volume analysis provides another broad statewide measure of the performance of the overall model. The truck traffic in the North area with 26 check points, the West area with 36 check points, the East area with 29 check points, and the South area with 64 check points are compared to the actual ground count totals. The four areas show similar results. No specific patterns in the L V/GC ratio by area are found. In addition, the %RMSE is computed for each of the four areas. The %RMSEs for the North, West, East, and South areas are 92%, 49%, 27%, and 35% respectively, whereas, the average ground counts are 481, 1383, 1532, and 3154 respectively. As for the screenline and volume range analyses, the %RMSE is inversely related to average link volume. 'The SELINK adjustments of productions and attractions resulted in a very substantial reduction in the total in-state zonal productions and attractions. The initial in-state zonal trip generation model can now be revised with a new trip production's trip rate (total adjusted productions/total population) and a new trip attraction's trip rate. Revised zonal production and attraction adjustment factors can then be developed that only reflect the impact of the SELINK adjustments that cause mcreases or , decreases from the revised zonal estimate of productions and attractions. Analysis of the revised production adjustment factors is conducted by plotting the factors on the state map. The east area of the state including the counties of Brown, Outagamie, Shawano, Wmnebago, Fond du Lac, Marathon shows comparatively large values of the revised adjustment factors. Overall, both small and large values of the revised adjustment factors are scattered around Wisconsin. This suggests that more independent variables beyond just 226; population are needed for the development of the heavy truck trip generation model. More independent variables including zonal employment data (office employees and manufacturing employees) by industry type, zonal private trucks 226; owned and zonal income data which are not available currently should be considered. A plot of frequency distribution of the in-state zones as a function of the revised production and attraction adjustment factors shows the overall " adjustment resulting from the SELINK analysis process. Overall, the revised SELINK adjustments show that the productions for many zones are reduced by, a factor of 0.5 to 0.8 while the productions for ~ relatively few zones are increased by factors from 1.1 to 4 with most of the factors in the 3.0 range. No obvious explanation for the frequency distribution could be found. The revised SELINK adjustments overall appear to be reasonable. The heavy truck VMT analysis is conducted by comparing the 1990 heavy truck VMT that is forecasted by the GM truck forecasting model, 2.975 billions, with the WisDOT computed data. This gives an estimate that is 18.3% less than the WisDOT computation of 3.642 billions of VMT. The WisDOT estimates are based on the sampling the link volumes for USH, 8TH, and CTH. This implies potential error in sampling the average link volume. The WisDOT estimate of heavy truck VMT cannot be tabulated by the three trip types, I-I, I-E ('||'&'||'pound;-I), and E-E. In contrast, the GM forecasting model shows that the proportion ofE-E VMT out of total VMT is 21.24%. In addition, tabulation of heavy truck VMT by route functional class shows that the proportion of truck traffic traversing the freeways and expressways is 76.5%. Only 14.1% of total freeway truck traffic is I-I trips, while 80% of total collector truck traffic is I-I trips. This implies that freeways are traversed mainly by I-E and E-E truck traffic while collectors are used mainly by I-I truck traffic. Other tabulations such as average heavy truck speed by trip type, average travel distance by trip type and the VMT distribution by trip type, route functional class and travel speed are useful information for highway planners to understand the characteristics of statewide heavy truck trip patternS. Heavy truck volumes for the target year 2010 are forecasted by using the GM truck forecasting model. Four scenarios are used. Fo~ better forecasting, ground count- based segment adjustment factors are developed and applied. ISH 90 '||'&'||' 94 and USH 41 are used as example routes. The forecasting results by using the ground count-based segment adjustment factors are satisfactory for long range planning purposes, but additional ground counts would be useful for USH 41. Sensitivity analysis provides estimates of the impacts of the alternative growth rates including information about changes in the trip types using key routes. The network'||'&'||'not;based GMcan easily model scenarios with different rates of growth in rural versus . . urban areas, small versus large cities, and in-state zones versus external stations. cities, and in-state zones versus external stations.

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Heterogeneous Interface Decision Engine and Architecture for Constructing Low Power Home Networks (저전력의 홈 네트워크 구축을 위한 이기종 인터페이스 결정 엔진 및 아키텍처)

  • Bae, Puleum;Jo, Yeong-Myeong;Moon, Eui-Kyum;Ko, Young-Bae
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.2
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    • pp.313-324
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    • 2015
  • In this paper, in order to support the construction of a smart home environment of low power consumption, we propose a heterogeneous interface determination engine and architecture. Technology of "smart home" is in the spotlight according to the development of IT technology nowadays. Smart homes are configured with multiple sub-networks, and each sub-network is formed by the smart devices using various communication interfaces. Thus, in the smart home environment, interlocking technology between heterogeneous interfaces is essentially required for supporting communication between different networks. Further, each communication interface is a difference in power consumption, and home smart devices are often operated in 24 hours, especially smart phones and other wireless devices are sensitive to power consumption. Therefore, in order to build a energy efficient home network, It is important to select the appropriate interface to handle traffic depending on the situation. In this paper, we propose "The Heterogeneous Interface Decision Engine and Architecture for constructing of Low Power Home Network," and analyze the performance of the proposed method and verify the validity through experiments on the test bed.

Development of Steel Composite Cable Stayed Bridge Weigh-in-Motion System using Artificial Neural Network (인공신경망을 이용한 강합성 사장교 차량하중분석시스템 개발)

  • Park, Min-Seok;Jo, Byung-Wan;Lee, Jungwhee;Kim, Sungkon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.6A
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    • pp.799-808
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    • 2008
  • The analysis of vehicular loads reflecting the domestic traffic circumstances is necessary for the development of adequate design live load models in the analysis and design of cable-supported bridges or the development of fatigue load models to predict the remaining lifespan of the bridges. This study intends to develop an ANN(artificial neural network)-based Bridge WIM system and Influence line-based Bridge WIM system for obtaining information concerning the loads conditions of vehicles crossing bridge structures by exploiting the signals measured by strain gauges installed at the bottom surface of the bridge superstructure. This study relies on experimental data corresponding to the travelling of hundreds of random vehicles rather than on theoretical data generated through numerical simulations to secure data sets for the training and test of the ANN. In addition, data acquired from 3 types of vehicles weighed statically at measurement station and then crossing the bridge repeatedly are also exploited to examine the accuracy of the trained ANN. The results obtained through the proposed ANN-based analysis method, the influence line analysis method considering the local behavior of the bridge are compared for an example cable-stayed bridge. In view of the results related to the cable-stayed bridge, the cross beam ANN analysis method appears to provide more remarkable load analysis results than the cross beam influence line method.

Data Mining Approaches for DDoS Attack Detection (분산 서비스거부 공격 탐지를 위한 데이터 마이닝 기법)

  • Kim, Mi-Hui;Na, Hyun-Jung;Chae, Ki-Joon;Bang, Hyo-Chan;Na, Jung-Chan
    • Journal of KIISE:Information Networking
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    • v.32 no.3
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    • pp.279-290
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    • 2005
  • Recently, as the serious damage caused by DDoS attacks increases, the rapid detection and the proper response mechanisms are urgent. However, existing security mechanisms do not effectively defend against these attacks, or the defense capability of some mechanisms is only limited to specific DDoS attacks. In this paper, we propose a detection architecture against DDoS attack using data mining technology that can classify the latest types of DDoS attack, and can detect the modification of existing attacks as well as the novel attacks. This architecture consists of a Misuse Detection Module modeling to classify the existing attacks, and an Anomaly Detection Module modeling to detect the novel attacks. And it utilizes the off-line generated models in order to detect the DDoS attack using the real-time traffic. We gathered the NetFlow data generated at an access router of our network in order to model the real network traffic and test it. The NetFlow provides the useful flow-based statistical information without tremendous preprocessing. Also, we mounted the well-known DDoS attack tools to gather the attack traffic. And then, our experimental results show that our approach can provide the outstanding performance against existing attacks, and provide the possibility of detection against the novel attack.

A Comparative Study of Aggregation Schemes for Concurrent Transmission over Multiple WLAN Interfaces (다중 무선랜 인터페이스 전송을 위한 결합 방식의 성능 연구)

  • Saputra, Yuris Mulya;Hwang, Hwanwoong;Yun, Ji-Hoon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.7
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    • pp.18-25
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    • 2014
  • To increase wireless capacity, the concurrent use of multiple wireless interfaces on different frequency bands, called aggregation, can be considered. In this paper, we focus on aggregation of multiple Wi-Fi interfaces with packet-level traffic spreading between the interfaces. Two aggregation schemes, link bonding and multipath TCP (MPTCP), are tested and compared in a dualband Wi-Fi radio system with their Linux implementation. Various test conditions such as traffic types, network delay, locations, interface failures and configuration parameters are considered. Experimental results show that aggregation increases throughput performance significantly over the use of a single interface. Link bonding achieves lower throughput than MPTCP due to duplicate TCP acknowledgements (ACKs) resulting from packet reordering and filtering such duplicate ACKs out is considered as a possible solution. However, link bonding is fast responsive to links' status changes such as a link failure. It is shown that different combinations of interface weights for packet spread in link bonding result in different throughput performance, envisioning a spatio-temporal adaptation of the weights. We also develop a mathematical model of power consumption and compare the power efficiency of the schemes applying different power consumption profiles.

MMT-based Broadcasting Services Combined with MPEG-DASH (MPEG-DASH 융합형 MMT 기반 방송 서비스)

  • Park, MinKyu;Kim, Yong Han
    • Journal of Broadcast Engineering
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    • v.20 no.2
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    • pp.283-299
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    • 2015
  • In this paper, we propose new broadcasting services that combine MMT (MPEG Media Transport) standard with MPEG-DASH (Dynamic Adaptive Streaming over HTTP) standard. MMT is a next-generation multimedia transport standard that is IP-friendly and provides functionalities appropriate for hybrid broadcasting that uses broadcast physical channels and the Internet simultaneously. MPEG-DASH enables media streaming services that can be dynamically adaptive both to the network traffic conditions of wired and/or wireless Internet and the receiving entity environment. We explain the scenarios of the proposed broadcasting services and demonstrate that various hybrid broadcasting services can be easily realized through the combined usage of MMT and MPEG-DASH. By making the test bitstreams containing contents for the new services and developing the receiver back-end software that performs the function of the receiving entity for the new services on personal computers, we verified that the proposed scenarios can be realized.

An Implementation of the Mobile Communication Simulator using a Object-Oriented Simulation Platform (객체지향적 시뮬레이션플랫폼을 이용한 이동통신 시뮬레이션 구현)

  • Yoon, Young-Hyun;Kim, Sang-Bok;Lee, Jeong-Bae
    • The KIPS Transactions:PartC
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    • v.11C no.5
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    • pp.613-620
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    • 2004
  • Traditionally, simulation method was used to test and evaluate the performance of communication protocol or functional elements for mobile communication service. In this Paper, PCSsim(Personal Communication System Simulator) was realized that can evaluate and review the call process of mobile communication service or to predict its performance by using the object-oriented simulation platform. PCSsim can simulate the base station and mobile host by considering the user's mobility, call generation rate and call duration time. In this paper, based on the simulation, presented the simulation results of hand-off generation ratio according to call generation, user's moving speed and call duration time both in residence area and commercial area, and it was confirmed that the hand-off rates in simulation and actual service environment have similar features. PCSsim can be used in adjusting the characteristics of base station fellowing the dynamic hand-off buffering or the characteristics of user's call in the design stage, and also can be used in building new mobile communication network by reflecting the characteristics of region where the base station is located and the mobility of the user.

Mutual Authentication Protocol based on the Effective Divided Session for the Secure Transmission of Medical Information in u-Health (유헬스에서 안전한 생체정보전송을 위한 동적인 유효세션기반의 상호인증 프로토콜)

  • Lee, Byung-Mun;Lim, Heon-Cheol;Kang, Un-Ku
    • The Journal of the Korea Contents Association
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    • v.11 no.2
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    • pp.142-151
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    • 2011
  • All medical information over sensor networks need to transmit and process securely in the u-Health services. The reliability of transmission between u-Health medical sensor devices and gateway is very important issue. When the user moves to other place with u-Health devices, its signal strength is going down and is far from the coverage of gateway. In this case, Malicious user can be carried out an intrusion under the situation. And also rogue gateway can be tried to steal medical information. Therefore, it needs mutual authentication between sensor devices and gateway. In this paper, we design a mutual authentication protocol which divided sessions from an authenticated session are updated periodically. And in order to reduce the traffic overhead for session authentication, we also introduce dynamic session management according to sampling rate of medical sensor type. In order to verify this, we implemented the programs for the test-bed, and got an overall success from three types of experiment.

Students injuries and Injury Surveillance System in Cheonan (손상감시체계를 통한 천안지역 초․중․고교생의 손상실태 분석)

  • Kang, Chang-Hyun;Kang, Hyun-A;Park, Jee-Hyun
    • Journal of the Korean Society of School Health
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    • v.22 no.2
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    • pp.157-167
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    • 2009
  • Purpose : The purpose of this study is to explore the students injuries by analyzing the data which has been inputted by the emergency center of the cooperated hospitals and the 119 rescue party through the injury surveillance system in Cheonan city. Method : Students were divided into the elementary, middle, high school students with the 776 cases of children and teenagers(7-19years old) of injury surveillance system in Cheonan area from january to june in 2009. Frequency analysis and $x^2$-test was done to recognize the features of students injuries among the groups. The program to be used for the statistical analysis is SPSS 17.0. Result : Out of the injury incidence rate, the elementary school students(52.1%) are first, the high school students (24.9%) are second, the middle school students appear to be 23.1%. Male is about two times higher than female by 66.6% in the injury incidence. In terms of the injury mechanism, the injury(22.2%) by hit is the first, the traffic accident(21.5%) is the second, the slippery(16.8%) is followed. The injuries were occurred most largely at 16:00-20:00(33.4%), and the 33.6% of injury by daily leisure activity occurs at 16:00-20:00 chiefly. Conclusion : Analysis using the data of the injury surveillance system has some advantages compared to the previous research such as reliability and specification. To prevent the students injuries, not the individual problem but the social dimension should be acknowledged so that we can secure and promote the safety from the risk. Therefore, we must organize the role assignment and the cooperative network in the school, home and community.