• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10A
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• pp.996-1002
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• 2006

USB(Universal Serial Bus) is one of the most popular communication interfaces. When USB is used in an extended range, especially configurating In-home network by connecting multiple digital devices each other, USB interface uses the bandwidth in the way of TDM (Time Division Multiplexing) so that the bottleneck of bus bandwidth can be brought. In this paper, the more effective usage of bus bandwidth to overcome this situation is introduced.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.402-408
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• 2002

Multicast technology allows the transmission of data from one source node to a selected group of destination nodes. Multicast routes typically use trees, called multicast routing trees, to minimize resource usage such as cost and bandwidth by sharing links. Moreover, the quality of service (QoS) is satisfied by distributing data along a path haying no more than a given number of arcs between the root node of a session and a terminal node of it in the routing tree. Thus, a multicast routing tree for a session can be represented as a hop constrained Steiner tree. In this paper, we consider the hop-constrained multicast route packing problem with bandwidth reservation. Given a set of multicast sessions, each of which has a hop limit constraint and a required bandwidth, the problem is to determine a set of multicast routing trees in an arc-capacitated network to minimize cost. We propose an integer programming formulation of the problem and an algorithm to solve it. An efficient column generation technique to solve the linear programming relaxation is proposed, and a modified cover inequality is used to strengthen the integer programming formulation.

• Spatial Information Research
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• v.20 no.4
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• pp.83-92
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• 2012

Location-based services (LBS) are increasingly popular due to the improvement of geo-positioning capabilities and wireless communication technology. However, in order to enjoy LBS services, a user requesting a query must send his/her exact location to the LBS provider. Therefore, it is a key challenge to preserve user's privacy while providing LBS. To solve this problem, the existing method employs a 2PASS cloaking framework that not only hides the actual user location but also reduces bandwidth consumption. However, 2PASS does not fully guarantee the actual user privacy because it does not take the real user distribution into account. Hence, in this paper, we propose a nearest neighbor query processing algorithm that supports K-anonymity property based on the weighted adjacency graph(WAG). Our algorithm not only preserves the location of a user by guaranteeing k-anonymity in a query region, but also improves a bandwidth usage by reducing unnecessary search for a query result. We demonstrate from experimental results that our algorithm outperforms the existing one in terms of query processing time and bandwidth usage.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.5
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• pp.724-729
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• 2008

This paper presents the calculation of the required bandwidth of common frequency bandwidth applying queueing theory for maximizing the efficiency of frequency resource of WPAN(Wireless Personal Area Network) based Digital acoustic and communication devices. It assumed that LBT device(ZigBee) and FH devices (DCP, RFID and Bluetooth) coexist in the common frequency band for WPAN based Digital acoustic and communication devices. Frequency hopping (FH) and listen before talk (LBT) have been used for interference avoidance in the short range device (SRD). The LBT system transmits data after searching for usable frequency bandwidth in the radio wave environment. However, the FH system transmits data without searching for usable frequency bandwidth. The queuing theory is employed to model the FH and LBT system, respectively. As a result, the throughput for each channel was analyzed by processing the usage frequency and the interval of service time for each channel statistically. When common frequency bandwidth is shared with SRD using 250mW, it was known that about 35 channels were required at the condition of throughput 84%, which was determined with the input condition of Gaussian distribution implying safety communication. Therefore, the common frequency bandwidth is estimated with multiplying the number of channel by the bandwidth per channel. These methodology will be useful for the efficient usage of frequency bandwidth.

• 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.

• The KIPS Transactions:PartC
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• v.16C no.4
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• pp.487-494
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• 2009

VOD(Video On Demand) that provides streaming service according to the user's requirement in real time, consists of the video streaming server and the client system. Since it is very hard to apply the traditional server-client model that a server communicates with many clients through 1:1 connection to VOD system because it requires very high network bandwidth, many researches have been done to address this problem. Batching technique is one of VOD system based on Multicast that requires very small network bandwidth. However, the batching based VOD system has a limitation that it is very hard to provide VCR(Video Cassette Recorder) ability. In this paper, we propose a technique that reduces the required network bandwidth to provide VCR function by using the characteristic of MPEG, one of international video compression standard. In the proposed technique, a new video stream for VCR function is constructed with I pictures that is able to be decoded independently. The new video stream for VCR function is transmitted with the video stream for normal play together in Batching manner. The performance evaluation result shows that the proposed technique not only reduces the required network bandwidth and memory usage but also decreases the CPU usages.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.25-28
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• 1999

Consider connection-oriented wireless cellular net-works. To establish a circuit or virtual circuit in such a network, a paging message is broadcast over a region at which the destined mobile station is presumed to reside, (identified as a paging area). For an effective paging mechanism, it is desirable to provide the location information of mobile stations to the network. In this paper, we consider a mobile controlled location update scheme under which each mobile station periodically reports its current location information to the network by using an inherent timer (without measuring the power of signals transmitted from base stations). Based on the latest information about a mobile station's location, a paging area is selected to page the mobile station. Note that under this scheme, a mobile station may not yet have reported its location change while sojourning out of the current paging area. In such situation, the mobile station can not receive a paging message destined to it. Frequent location updates can reduce the paging failure rate incurred by mobile stations'sojourning out of the paging area. However, larger bandwidth is needed for location update as the location update rate is increased. On the other hand, as the size of the paging area is increased, the paging failure rate is decreased, while larger bandwidth is required for paging. Thus, we first present a model for mobility, paging and location update processes, and secondly investigate the effect of network parameters on the paging failure rate and the amount of bandwidth used for paging and location update. Finally, we formulate problems to find proper values for the location update rate and paging area size under the constraints on the bandwidth usage levels for location update and paging.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.2 s.58
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• pp.38-49
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• 2006

In order to increase the spectrum efficiency, recently, there is the number of studies for CR technology. For instance, IEEE 802.22 WRAN(Wireless Regional Area Network) WG considered the CR technology as a solution of WRAN system to serve the high speed internet service(1.5 Mbps down stream and 384 kbps up stream) in 100 km overall coverage and 54 MHz-746 MHz band. Basically, in MAC point of view, the WRAN system have been standardizing based on the IEEE 802.16 MAC layer features such as Data transmission method, QoS provision and Bandwidth request schemes. Additionally, the WRAN system further include CR nature functions such as incumbent user protection, self coexistence which would be importantly considered. Also, the inherent WRAN functions are added such as channel bonding and fractional bandwidth usage. This paper mainly explained frame structure, IU protection, self coexistence which are key functions of WRAN system. Finally, in this paper, we expressed a prospect of IEEE 802.22 WRAN standardization.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5B
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• pp.324-329
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• 2005

In the traditional telephone services, the settlement method for usage of facilities has been systematically and reasonably arranged based on the cost. Through the advanced technology, the telecommunication services such as the convergence of voice-data, wire-wireless, communication-broadcasting, etc are offering. So, new settlement method in the broadband convergence network (BCN) should be necessary. This paper suggests inter-companies settlement method in the broadband network using interconnection bandwidth and transmission distance factor. By reflecting the facility cost weight on each BCN level, the cost settlement for various services can be easily done. As the settlement model for BCN, the inter-companies interconnection and settlement can be normalized by interconnection bandwidth and transmission distance factors.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.1
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• pp.153-161
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• 2022

This paper analyzes the economic effects when platform provider including CP contributes to broadband universal service and uses broadband bandwidth providing high quality network service. In this model, the contribution rate of broadband universal service is determined by ISP and platform provider sets its price of contents. The main results are as follows. First, the traffic usages is less than social optimum when the market of contents is monopoly. The sum of contribution fee and network usage rate must be less than marginal cost of network operation to get social optimum traffic. Second, the rate set by ISP is equal to social optimum when the market of contents is competitive. Third, when platform provider does not charge contents provided, ISP sets social optimum prices and the network usage rate for contents user is decreasing as advertisement revenue becomes larger. These results suggest that the platform provider should contribute to universal service funding to encourage the network investment of ISP.