• Journal of Information Technology and Architecture
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• v.10 no.2
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• pp.159-167
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• 2013

Web Services offer many benefits over other types of middleware in distributed computing. However, usage of Web Services results in large network bandwidth since Web Services use XML-based protocol which is heavier than binary protocols. Even though there have been many researches to minimize the network traffic and bandwidth usages of Web Services messages, none of them are solving problem clearly yet. In this paper, we propose a transparent proxy with cache to avoid transfer of repeated SOAP data, sent by Web Service to an application. To maintain the cache consistency, we introduce publish/subscribe paradigm using WS-Eventing between the proxy and Web Service. The implemented system based on our proposed architecture will not compromise the standards of Web Service. The evaluation of our system shows that caching SOAP messages not only reduces the network traffic but also decreases the request delays.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.541-544
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• 2000

This paper presents a multitier GIS architecture to adapt to large-scale distributed networks and to improve data transfer performance with intelligent caching technique. We design this system using UML based on object-oriented analysis. We show some advantages in our proposed system against the ordinary GIS, in special, suitability to distributed networks.

• ETRI Journal
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• v.30 no.2
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• pp.194-204
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• 2008

The online collection of coarse-grained traffic information, such as the total number of flows, is gaining in importance due to a wide range of applications, such as congestion control and network security. In this paper, we focus on an active queue management scheme called SRED since it estimates the number of active flows and uses the quantity to indicate the level of congestion. However, SRED has several limitations, such as instability in estimating the number of active flows and underestimation of active flows in the presence of non-responsive traffic. We present a Markov model to examine the capability of SRED in estimating the number of flows. We show how the SRED cache hit rate can be used to quantify the number of active flows. We then propose a modified SRED scheme, called hash-based two-level caching (HaTCh), which uses hashing and a two-level caching mechanism to accurately estimate the number of active flows under various workloads. Simulation results indicate that the proposed scheme provides a more accurate estimation of the number of active flows than SRED, stabilizes the estimation with respect to workload fluctuations, and prevents performance degradation by efficiently isolating non-responsive flows.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.9
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• pp.38-45
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• 2007

With the emergence of new applications, packet classification is essential for supporting advanced internet applications, such as network security and QoS provisioning. As the packet classification on multiple-fields is a difficult and time consuming problem, internet routers need to classify incoming packet quickly into flows. In this paper, we present multi-phase packet classification architecture using an internal buffer for fast packet processing. Using internal buffer between address pair searching phase and remained fields searching phases, we can hide latency from the characteristic that search times of source and destination header fields are different. Moreover we guarantee the improvement by using single entry caching. The proposed architecture is easy to apply to different needs owing to its simplicity and generality.

• Journal of Korea Multimedia Society
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• v.16 no.12
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• pp.1403-1412
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• 2013

In the maritime ships or airplanes, users should utilize the satellite channel in orer to use web service. However, the satellite channel is costly and does not give users satisfied response time. In the ship, the users may receive plenty of extra data when they obtain internet news. The extra data may be unnecessary image and advertise. Therefore, they should pay unnecessary data usage charges as well. In this paper, we suggest a proxy model that solves the problem of cost and speed. The proposed proxy reduces the of data through the satellite link by image and advertising blocking, caching, image re-requesting functions. It's performance was tested by a real satellite communication.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.3
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• pp.919-940
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• 2012

Video on Demand (VOD) is a multimedia service which allows a remote user to select and then view video at his convenience at any time he wants, which makes the VOD become an important technology for many applications. Numerous periodic VOD broadcasting protocols have been proposed to support a large number of receivers. Broadcasting is an efficient transmission scheme to provide on-demand service for very popular movies. This paper proposes a new broadcasting scheme called Popularity Cushion Staggered Broadcasting (PCSB). The proposed scheme improves the Periodic Broadcasting (PB) protocols in the latest mobile VOD system, which is called MobiVoD system. It also, reduces the maximum waiting time of the mobile node, by partitioning the $1^{st}$ segment of the whole video and storing it in the Local Media Forwarder (LMF) exactly in the Pool of RAM (PoR), and then transmitting them when the mobile nodes miss the $1^{st}$ broadcasted segment. The results show that the PCSB is more efficient and better than the all types of broadcasting and caching techniques in the MobiVoD system. Furthermore, these results exhibits that system performance is stable under high dynamics of the system and the viewer's waiting time are less than the previous system.

• Journal of information and communication convergence engineering
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• v.11 no.3
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• pp.173-178
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• 2013

To discover objects of interest in unstructured peer-to-peer networks, the peers rely on flooding query messages which create incredible network traffic. This article evaluates the performance of an unstructured Gnutella-like protocol over mobile ad-hoc networks and proposes modifications to improve its performance. This paper offers an enhanced mechanism for an unstructured Gnutella-like network with improved peer features to better meet the mobility requirement of ad-hoc networks. The proposed system introduces a novel caching optimization technique and enhanced ultrapeer selection scheme to make communication more efficient between peers and ultrapeers. The paper also describes an enhanced query mechanism for efficient searching by applying multiple walker random walks with a jump and replication technique. According to the simulation results, the proposed system yields better performance than Gnutella, XL-Gnutella, and random walk in terms of the query success rate, query response time, network load, and overhead.

• Journal of Advanced Navigation Technology
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• v.10 no.2
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• pp.120-127
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• 2006

Data-caching of a client is an important technology for interaction with a server where data are cached and operated at the client node. Caching reduces network latency and increases resource utilization at the client. In a Client-server environment, the absence of cache consistency algorithm, we cannot guarantee the correctness of client applications. In this paper, we propose a new asynchronous avoidance-based cache consistency algorithm. We remove the additional callback due to the lock escalation in AACC. With a comprehensive performance analysis, we show that the proposed algorithm has less message exchange than the AACC. One-copy serializability is used for proving correctness of the proposed algorithm.

• Journal of Internet Computing and Services
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• v.15 no.1
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• pp.135-142
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• 2014

In this paper, we present integrated SNS Gateway as way to reduce mobile SNS traffic. Integrated SNS gateway's role is communication broker that located between mobile clients and SNS server. In Integrated SNS gateway, web service adapter communicates with SNS Server. Experiment was performed in aspects of contents RTT and network traffic. We evaluate and propose performances of integrated SNS gateway using gateway.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.201-204
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• 2002

Although the reuse of the cached data for scrolling the map reduces the amount of passed data between client and server, it needs the conversions of data coordinates, selective deletion of objects and cache compaction at client. The conversion is time intensive operation due to limited resources of mobile phones such as low computing power, small memory. Therefore, for the efficient map control in the vector map service based mobile phone, it is necessary to study the method for reducing wireless network bandwidth and for overwhelming the limited resources of mobile phone as well. This paper proposes the methods for caching pre-received spatial objects in client-server systems for mobile GIS. We also analyze the strengths and drawbacks between the reuse of cached data and transmission of raw data respectively.