• Journal of KIISE:Information Networking
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• v.31 no.2
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• pp.131-145
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• 2004

Mobile IP has been designed only to maintain communications as mobile devices move from a place to a place, so it does not guarantee Quality of Service (QoS). Hierarchical MIPv6 improved QoS somewhat using Mobility Anchor Point(MAP), but QoS guarantee problem still remains. QoS in mobile IP is important to provide multimedia and real-timeapplications services in a mobile environment, and QoS is closely related to handoff delay. Therefore, handoff delay problem is actively studied as a main issue in mobile IP research area to guarantee QoS. In this paper, we suggest SNMP Information-based routing that adds keyword management method to Information-based routing in an active network in order to resolve such a problem, Suggested QoS controlled method and existing handoff method, simulations are carried out with NS-2 for performance evaluation. The results of simulations show an improvement on handoff delay, and consequently the QoS improvement.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.2
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• pp.344-358
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• 2011

Wireless tactical network (WTN) is the most important present-day technology enabling modern network centric warfare. It inherits many features from WMNs, since the WTN is based on existing wireless mesh networks (WMNs). However, it also has distinctive characteristics, such as hierarchical structures and tight QoS (Quality-of-Service) requirements. Little research has been conducted on hierarchical protocols to support various QoS in WMN. We require new protocols specifically optimized for WTNs. Control packets are generally required to find paths and reserve resources for QoS requirements, so data throughput is not degraded due to overhead. The fundamental solution is to adopt topology aggregation, in which a low tier node aggregates and simplifies the topology information and delivers it to a high tier node. The overhead from control packet exchange can be reduced greatly due to decreased information size. Although topology aggregation is effective for low overhead, it also causes the inaccuracy of topology information; thus, incurring low QoS support capability. Therefore, we need a new topology aggregation algorithm to achieve high accuracy. In this paper, we propose a new aggregation algorithm based on star topology. Noting the hierarchical characteristics in military and hierarchical networks, star topology aggregation can be used effectively. Our algorithm uses a limited number of bypasses to increase the exactness of the star topology aggregation. It adjusts topology parameters whenever it adds a bypass. Consequently, the result is highly accurate and has low computational complexity.

• The KIPS Transactions:PartC
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• v.9C no.5
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• pp.671-678
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• 2002

In this paper, we propose hierarchical inter-domain load balanced QoS routing in a large scale of network. And a scheme of calculating resources'costs for precomputation schemes in hierarchical routing is proposed, and a scheme for selecting a path among multiple precomputed paths is proposed. We also propose a QoS routing scheme for transit and intra traffic in a large scale of domain-based network. For a domain in the network, the routing scheme first precomputes K multiple paths between all pairs of ingress and egress border routers while considering balancing of the expected load then selects paths with the probability of path selection. The routing scheme combines inter and intra domain routings seamlessly and uses the same cost calculation scheme. And these schemes make possible both global network resources' utilization and also load balancing.

• Journal of the Korea Society of Computer and Information
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• v.10 no.3 s.35
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• pp.209-217
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• 2005

In this paper, we propose hierarchical inter-domain load balanced QoS routing in a large scale of network. And a scheme of calculating resources' costs for precomputation schemes in hierarchical routing is proposed. and a scheme for selecting a path among multiple precomputed paths is proposed. We also propose a QoS routing scheme for transit and intra traffic in a large scale of domain-based network. For a domain in the network, the routing scheme first precomputes K multiple paths between all pairs of ingress and egress border routers while considering balancing of the expected load then selects paths with the probability of path selection. The routing scheme combines inter and intra domain routings seamlessly and uses the same cost calculation scheme.

• Journal of information and communication convergence engineering
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• v.12 no.1
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• pp.14-18
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• 2014

A recent major development in computer technology is the advent of wearable computer systems. Wearable computer systems employ a wireless universal serial bus (WUSB), which refers to a combination of USB with the WiMedia wireless technical specifications. In this study, we focus on an integrated system of WUSB over wireless body area networks (WBANs) for wireless wearable computer systems. However, current WBAN MACs do not have well-defined quality of service (QoS) mapping and resource allocation mechanisms to support multimedia streams with the requested QoS parameters. To solve this problem, we propose a novel QoS-aware time slot allocation method. The proposed method provides fair and adaptive QoS provisioning to isochronous streams according to current traffic loads and their requested QoS parameters by executing a QoS satisfaction algorithm at the WUSB/WBAN host. The simulation results show that the proposed method improves the efficiency of time slot utilization while maximizing QoS provisioning.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10B
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• pp.947-956
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• 2003

The current IP Routing Protocolspacket networks also need to provide the network QoS based of DiffServ, RSVP, MPLStraffic model which is standardized as IETF reference model for NGN. The first topic of this paper is to propose Traffic-Balanced Routing Protocol(TBRP) to process existing best effort traffic. TBRP will process low priority interactive data and background data which is not sensitive to dealy. Secondly Hierarchical Traffic-Traffic-Scheduling Routing Protocol(HTSRP) is also proposed. HTSRP is the hierarchical routing algorithm for backbone and access networkin case of fixed-wireless convergence network. Finally, HTSRP_Q is proposed to meet the QoS requirement when user want interactive or streaming packet service. This protocol will maximize the usage of resources of access layer based on the QoS parameters and process delay-sensitive traffic. Service classes are categorized into 5 types by the user request, such as conversational, streaming, high priority interactive, low priority interactive, and background class. It could be processed efficiently by the routing protocolstraffic model proposed in this paper. The proposed routing protocolstraffic model provides the increase of efficiency and stability of the next generation network thanks to the routing according to the characteristic of the specialized service categories.

• The KIPS Transactions:PartC
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• v.18C no.5
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• pp.361-368
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• 2011

In this study, we present a method for efficiently aggregating networks state information required to determine feasible paths in transport networks that uses the source routing algorithm for hierarchical QoS routing. It is proposed to transform the full mesh topology whose Service Boundary Line serves as its logical link into the star topology. This is an aggregation method that can be used when there are two or more QoS parameters for the link to be aggregated in an asymmetric network, and it improves the information accuracy of the star topology. For this purpose, the Service Boundary Line's 3 attributes, splitting, joining and integrating, are defined in this study, and they are used to present a topology transformation method. The proposed method is similar to space complexity and time complexity of other known techniques. But simulation results showed that aggregated information accuracy and query response accuracy is more highly than that of other known method.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.6
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• pp.11-18
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• 2009

In this paper, a hierarchical link allocation algorithm between mobile stations (MSs) and the corresponding base station (BS) by an optimal utilization of relay stations (RSs) is proposed to improve throughput of RS systems. In the proposed hierarchical algorithm, each RS operates cognitive radio functions to sense the degree of satisfaction in the quality of services (QoSs) and then selects the candidate set of MSs to have links with the RS. Such information is reported to the BS, where an auction process is performed to get an optimal allocation of communication links between the MSs and the BS. To maximize system throughput, the proposed auction algorithm is conducted upon bidding prices of communication links, considering both the co-channel interference (CCI) information shared among adjacent cells and the QoS enhancement information for each MS collected from RSs. The BS then switches the communication links of the auction winner MSs through the corresponding RS. The computer simulation shows that the proposed algorithm enhances the user QoS more than the conventional algorithm, especially for RS systems with more users requiring higher QoS. The proposed algorithm has also been proved to have more robust performance than the conventional one when the traffic load is higher and the CCI becomes stronger.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.12B
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• pp.1066-1080
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• 2003

In this paper a scalable QoS routing scheme for distributed multimedia applications in a hierarchical wide area network is proposed. The problem of QoS routing is formulated as a multicriteria shortest path problem, known as NP-complete. The proposed hierarchical routing scheme consists of two phases. In Phase 1, every border node periodically pre-computes the QoS distance for the paths between every pair of border nodes in any level of domain hierarchy. This phase is independet of the QoS request from an application. In Phase II, distributed graph construction algorithm is performed to model the network as a graph by retrieving pre-computed QoS distances. The graph is constructed by the on-demand algorithm and contains a part of the network topology which is completely neglected or partially considered by existing routing schemes, thus maintaining more accurate topology information. By using retrieval approach rather than advertising one, no global QoS state information exchange among nodes is needed. In this Phase, distributed partition algorithm for QoS routing problem is also performed, thus eliminating virtual links on the hierarchically complete path.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.11
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• pp.675-690
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• 2003

In this paper, we present the virtual dancing studio for distributed virtual environment. In this system, geographically distributed user shares the virtual dancing hall and interacts with each other. The participating object can be a graphical avatar or a live video stream. It allows the coexistence of graphic objects and real images in the shared virtual space. One of the main technical challenges in developing the distributed virtual environment is to handle excessive network traffic. In an effort to effectively reduce the network traffic, we propose a scheme to adjust the QoS of each object with respect to the distance from the observer in the virtual space. The server maintains the QoS vector for each client's shared space and controls the packet traffic to individual clients based on its QoS vectors. We develop a proto-type virtual dancing environment. Java based development enables the client to be platform independent. The result of experiment shows that the adoption of hierarchical QoS management significantly reduces the overall network traffic.