• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.6B
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• pp.433-442
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• 2012

We have proposed a solution to multicast services and an advanced quality of service (QoS) mechanism on a packet transport system (PTS) based on PBB-TE. The point-to-multipoint (PtMP) connection in the PBB-TE system have been realized by grouping point-to-point (PtP) PTL trunks and mapping a BSI onto the PtP PTL trunks using a multicast backbone destination address. To provide end-to-end QoS of the PtMP services, the hierarchical QoS scheme for backbone service instances and connection-oriented paths has been implemented in the PTS. For providing different capabilities for service selection and priority selection, the PTS offers to customers three basic types of the port-based, C-tagged, and S-tagged service interface defined by the IEEE 802.1ah. To offer to customers different capabilities of the layer 3 applications and services, moreover, an IP-flow service interface have been added. In order to evaluate traffic performance for PtMP services in the PTS, the PtMP throughputs for the link capacity of 1 Gbps at the four service interfaces were measured in the leaves of the ingress edge node, the transit node, and the egress edge node. The throughputs were about 96 % because the B-MAC overhead of 22 bytes occupies 4% of the 512-byte packet. The QoS performance is ability to guarantee an application or a user a required bandwidth, and could be evaluated by the accuracy of policing or shaping. The accuracy of the policing scheme and the accuracy of the shaping scheme were 99% and 99.3% respectively.

• Electronics and Telecommunications Trends
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• v.35 no.2
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• pp.17-27
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• 2020

Predicting where and when a crime may occur in an area of interest is one of many strategies of predictive policing. Multidimensional analysis, including CCTV, can overcome the limitations of hotspot prediction, especially of violent crimes. In order to identify the precursors of a crime, it is necessary to analyze dynamic data such as attributes and activities of people, social information, environmental information, traffic flows, and weather. These parameters can be recognized by CCTV. In addition, it provides accurate analysis of the circumstances of a crime in a dynamic situation, calculates the risk, and predicts the probability of a crime occurring in the near future. Additionally, it provides ways to gather historical criminal datasets, including sensitive personal information.

• The Journal of the Korea Contents Association
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• v.9 no.9
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• pp.199-209
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• 2009

By materials of traffic safety public corporation, from 2007. 1. 1 to 2007 12. 31, for a year. traffic accidents took place in korea were 211,662 accidents. By this 6,166 people were death, and 335,906 people were wounded. In Gwangju metropolitan city, in 2007 year, 7,881 accidents took place and 152 people were death and 12,728 peoples were wounded, in 2008 year, 8,231 accidents took place and 138 people were death and 13,533 people were wounded. Death people reduced but accidents numbers were in creased 4.4%. Meanwhile, government did various traffic policies to reduce traffic accident. But still, disgrace of underdeveloped country in traffic division couldn't take off. Moreover, traffic safety unconcern of general country people are very deficient. In this research, as the basis of Gwangju province police agency, in traffic accident the present state, I am' going to analyse the part of directly related to citizen life and centering death accident and to present traffic police activities for prevention of traffic accidents.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.7B
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• pp.1261-1267
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• 1999

Frame relay (FR) service via an FR interface over a common asynchronous transfer mode (ATM) backbone network requires an FR-to-ATM interworking unit (IWU), the functionality of which directly impacts the engineering of the overall network in terms of capacity required, quality of service (QoS), and the interference among different types of services. This paper presents performance analysis of frame relay traffic in IWU. Additionally frame relay traffic policing using leaky bucket algorithm in this traffic model is carried out through computer simulation. Three measurements, the percentage of frames accepted as committed, the percentage of frames that accepted but marked eligible for diacard, and the percentage of frames that accepted that are discarded because of insufficient number of credits, are simulated variously in this paper.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.2
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• pp.23-31
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• 1996

This paper proposes a new UPC(usage parameter control) mechanism that varies the token generation rate of leaky bucket by observing virtual buffer, thus achieving an improvement of performance. An acceptance of a call in B-ISDN is determined by call admission control. A UPC that polices the agreed traffic parameters of a call and takes appropriate actions to prevent congestion in networks. The cell loss probability of conventional UPC is far from that of ideal UPC. The proposed mechanism has a better policing ability and response time for nonconforming call. The proposed mechanism uses ON-OFF model as input traffic. The results of simulation show the efficiency of the proposed mechanism.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.17 no.2
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• pp.103-113
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• 2013

We analyze the queueing model for leaky bucket (LB) scheme with dynamic arrivals and token rates. In other words, in our LB scheme the arrivals and token rates are changed according to the buffer occupancy. In telecommunication networks, the LB scheme has been used as a policing function to prevent congestion. By considering bursty and correlated properties of input traffic, the arrivals are assumed to follow a Markov-modulated Poisson process (MMPP). We derive the distribution of system state, and obtain the loss probability and the mean waiting time. The analysis is done by using the embedded Markov chain and supplementary variable method. We also present some numerical examples to show the effect of our proposed model.

• The Transactions of the Korea Information Processing Society
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• v.6 no.1
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• pp.175-181
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• 1999

There are issues regarding how some of traffic parameters should be set so that ATM and non-ATM service parameters can be compatible. For example, policing method used by frame relay based on CIR(committed information rate) will not exactly match the ATM UPC(Usage Parameter Control) method. ATM and the frame relay have different transfer modes and traffic parameters. The cells and frames are police by their own traffic control schemes. For the same information, the real traffic of the ATM side takes greater bandwidth than that of the frame relay side caused by ATM cell format and AAL5 format. IN both networks this bandwidth than that of the frame relay side caused by ATM cell format and AAL5 format. In both networks this bandwidth ratio should be considered on traffic parameter mapping to maintain their QoS and to perform efficient network resource management. In this paper we describe traffic parameter mapping schemes between frame relay and ATM in ATM network and how to expect the bandwidth ratio to maintain FR QoS in ATM network. We assumed frame length distribution to Erlang or Exponential probability density function.

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.2
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• pp.60-64
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• 2006

In typical video streaming services such as MPEG encoded video, the transmission data sizes change depending on the frame types and the required bandwidth for QoS support also changes as time passes. Accordingly, in video streaming services using the Internet it could happen that the video services stop occasionally due to instantaneous deficiencies of the required bandwidth under unexpected congestion even if the highest priority is allocated to the service by network administration. In this paper, we investigate several methods for bandwidth allocation and traffic engineering to support MPEG video traffic and propose a new method to reduce the transmission delay and enhance the throughput, there by provisioning the QoS requirements. In the proposed scheme, LSPs are established based on temporal variation patterns of the Internet traffic and the CQ_LLQ policing scheme is applied for traffic shaping at the ingress routers. Finally we verified the performance of the proposed scheme via computer simulations using OPNET.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.6
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• pp.1480-1489
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• 1996

In ATM networks there are two methods in traffic control as schemes advancing the quality of service. One is reactive control after congestion and the other which is generally recommended, is preventive control before congestion, including connection admission control on call leel and usage parameter control, network parameter control, priority control and congestion control on cell level. In particular, usage parameter control is required for restricting the peak cell rate of bursy tracffic to the parameter negotiated at call set-up phase since the peak cell rate significantly influences the network quality of service. The scheme for progressing quality of service by usage parameter control is themethod using VSA(Virtual Scheduling Algorlithm) recommended ITU-T. The method using VSSA(Virtual Scheduling Suggested Algorlithm) in this paper is suggested by considering cell delay variation and token rate of leaky bucket, compared VSA and VSANT(Virtual Scheduling Algolithm with No Tolerance) with VSSA which polices violated cell probability of conformed peak cell rate and intentionally excessive peak cell rate. VSSA method using IPP(Interruped Poisson Process) model of input traffic source showed more quality of service than VSA and VSANT methods as usage parameter control because the suggested method reduced the violated cell probability of contformed peak cell rate and intentionally excessive peak cell rate.

• Communications of the Korean Mathematical Society
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• v.13 no.3
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• pp.603-627
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• 1998

The leaky bucket scheme is a promising method that regulates input traffics for preventive congestion control. In the ATM network, the input traffics are bursty and transmitted at high-speed. In order to get the low loss probability for bursty input traffics, it is known that the leaky bucket scheme with static leaky rate requires larger data buffer and token pool size. This causes the increase of the mean waiting time for an input traffic to pass the policing function, which would be inappropriate for real time traffics such as voice and video. We present the leaky bucket scheme with dynamic leaky rate in which the token generation period changes according to buffer occupancy. In the leaky bucket scheme with dynamic leaky rate, the cell loss probability and the mean waiting time are reduced in comparison with the leaky bucket scheme with static leaky rate. We analyze the performance of the proposed leaky bucket scheme in discrete-time case by assuming arrival process to be Markov-modulated Bernoulli process (MMBP).