• Journal of Communications and Networks
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• v.17 no.4
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• pp.428-439
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• 2015

In this study, we present an approach for reducing the information inaccuracy of existing star aggregation based on bypass links when there are multi-constraint QoS parameters in asymmetric networks. In our approach, bypass links with low similarity are selected. Links that are not chosen as bypass links are included in each group depending on the star's link characteristics. Moreover, each link group is aggregated differently according to the similarity of the links that make up the group. The selection of a bypass link by using link similarity reduces the existing time complexity of O($N^3$) to O(N) by virtue of the simplification of the selection process. In addition, the adaptive integration according to the characteristics of the links in each group is designed to reduce the information inaccuracy caused by static aggregation. Simulation results show that the proposed method maintains low information distortion; specifically, it is 3.8 times lower than that of the existing method, even when the number of nodes in a network increases.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.331-334
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• 2005

This paper suggests the Ethernet aggregation to XGMII framing procedure (EAXFP) mechanism to economically combine the traffic adaptation technology with the link aggregation method in designing 10 Gigabit Ethernet (10 GbE) interfaces. This design sidesteps the data-loss issues that can result from designing an interface with only one link. The most critical issue in relation to the link aggregation interface is the algorithm used to control frame distribution between the ten ports. The proposed EAXFP mechanism offers an efficient link aggregation method as well as an efficient frame distribution algorithm, which maximize the throughout of the 10 GbE interface. In the experiment and analysis of the proposed mechanism, it was also discovered that the 10 GbE interface that uses the proposed EAXFP mechanism significantly reduced the packet loss rate. When there will be heavy traffic loads come about in the future, the proposed EAXFP mechanism assures an efficient and economical transmission performance on the router system.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.3
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• pp.150-154
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• 2011

The technology to build high speed network using low cost DSL in the areas where the cost to build high speed network is high and the network environment is not very accommodating is important in providing the high speed network that meets the user demand and utilizing the network resources in an efficient way. This study presents development of the link aggregation equipment that performs the access control and firewall functions for packet processing based LAN users. The equipments developed support up to 5 line link aggregation as opposed to current 2 line link aggregation. The equipments also allow the use of high speed network in the areas where the network environment is not very accommodating. Also, the fail-over function is added to each line to provide reliability and the self-security function is enhanced to protect the network from unauthorized use and prevents waste of network resources by authorized users.

• Journal of information and communication convergence engineering
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• v.3 no.1
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• pp.13-17
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• 2005

The link e daggregation between 10GbE switches requires an advanced framistribution method to be properly and efficiently applied. The fixed or dynamic frame distribution methods, formerly proposed, cannot fully utilize the aggregated links, where the receiving terminal only attaches to a pre-specified link among multiple physical links. A frame distribution method using padding is proposed for the link aggregation between 10GbE switches to solve this problem. We compared the performance of the proposed method with those of the static and dynamic frame distribution methods. As a result, the proposed method shows a better performance when the offered load is below 0.7 and the average length of the frames is longer than 954 bytes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.12A
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• pp.945-950
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• 2003

The link aggregation between 10GbE switches requires an advanced frame distribution method to be properly and efficiently applied. The fixed or dynamic frame distribution methods, formerly proposed, cannot fully utilize the aggregated links, where the receiving terminal only attaches to a pre-specified link among multiple physical links. A frame distribution method using tagging is proposed for the link aggregation between 10GbE switches to solve this problem. We compared the performance of the proposed method with those of the fixed and dynamic frame distribution methods. As a result, the proposed method shows a better performance when the applied load is below 0.7 and the average length of the frames is longer than 954 bytes.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.6
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• pp.1064-1070
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• 2010

Korea Department of Defense has been developing Link-K, Korean Joint Tactical Datalink, to support their independent joint operations and trying to enlarge the scope of Link-K tactical message delivery to nodes in IP based tactical networks for sharing situation awareness more broadly. A Link-K tactical message size is too small to fit into an IP packet, inefficiently wasting most of the IP packet space of the low bandwidth IP-based tactical networks. This paper proposes a new Link-K tactical message aggregation and delivery method when tactical messages need to be sent to some nodes located at IP-based tactical networks. With numerical analysis and OPNET simulation studies, we prove the effectiveness and efficiency of the proposed method.

• Journal of Communications and Networks
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• v.12 no.3
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• pp.209-215
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• 2010

In an asymmetrical speed channel environment like asymmetric digital subscriber line, the up-link bandwidth is normally smaller than the down-link bandwidth, which will lead to extremely low utilization of down-link bandwidth when current P2P video transmission is applied. To overcome this, a new fast P2P video transmission method applied in an asymmetrical speed channel environment is proposed in this paper. On the basis of the many-to-one concept, the proposed method uses a new multipeer aggregation technique to enhance the utilization of down-link bandwidth. In addition, an adaptive peer assignment algorithm is also introduced in order to minimize the overall transmission time. Experimental results show that by using our proposed method, the utilization of down-link bandwidth is significantly improved, and the overall transmission time is greatly reduced.

• Journal of Communications and Networks
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• v.6 no.1
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• pp.46-59
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• 2004

In this paper, we present two algorithms for efficiently aggregating link state information needed for quality-of-service (QoS) routing. In these algorithms, each edge node in a group is mapped onto a node of a shufflenet or a node of a de Bruijn graph. By this mapping, the number of links for which state information is maintained becomes aN (a is an integer, N is the number of edge nodes) which is significantly smaller than N2 in the full-mesh approach. Our algorithms also can support asymmetric link state parameters which are common in practice, while many previous algorithms such as the spanning tree approach can be applied only to networks with symmetric link state parameters. Experimental results show that the performance of our shufflenet algorithm is close to that of the full-mesh approach in terms of the accuracy of bandwidth and delay information, with only a much smaller amount of information. On the other hand, although it is not as good as the shufflenet approach, the de Bruijn algorithm also performs far better than the star approach which is one of the most widely accepted schemes. The de Bruijn algorithm needs smaller computational complexity than most previous algorithms for asymmetric networks, including the shufflenet algorithm.

• 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.

• Journal of Korean Society of Transportation
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• v.18 no.3
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• pp.55-76
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• 2000

We propose a general solution methodology for identifying the optimal aggregation interval sizes as a function of the traffic dynamics and frequency of observations for four cases : i) link travel time estimation, ii) corridor/route travel time estimation, iii) link travel time forecasting. and iv) corridor/route travel time forecasting. We first develop statistical models which define Mean Square Error (MSE) for four different cases and interpret the models from a traffic flow perspective. The emphasis is on i) the tradeoff between the Precision and bias, 2) the difference between estimation and forecasting, and 3) the implication of the correlation between links on the corridor/route travel time estimation and forecasting, We then demonstrate the Proposed models to the real-world travel time data from Houston, Texas which were collected as Part of the Automatic Vehicle Identification (AVI) system of the Houston Transtar system. The best aggregation interval sizes for the link travel time estimation and forecasting were different and the function of the traffic dynamics. For the best aggregation interval sizes for the corridor/route travel time estimation and forecasting, the covariance between links had an important effect.