• International Journal of Contents
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• v.1 no.2
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• pp.31-34
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• 2005

The new realtime applications like multimedia and realtime services in a wireless network will be dramatically increased. However, many realtime services of mobile hosts in a cell cannot be continued because of insufficiency of useful channels. Conventional channel assignment approaches didn't properly consider the problem to serve realtime applications in a cell. This paper proposes a new realtime channel assignment algorithm based on time constraint analysis of channel requests. The proposed algorithm dynamically borrows available channels from neighboring cells. It also supports a smooth handoff which continuously serves realtime applications of the mobile hosts.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.3 no.1
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• pp.18-22
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• 2003

The new realtime applications like multimedia and realtime services in a wireless network will be dramatically increased. However, many realtime services of mobile hosts in a cell cannot be continued because of insufficiency of useful channels. Conventional channel assignment approaches didn't properly consider the problem to serve realtime applications in a cell. This paper proposes a new realtime channel assignment algorithm based on time constraint analysis of channel requests. The proposed algorithm dynamically borrows available channels from neighboring cells. It also supports a smooth handoff which continuously serves realtime applications of the mobile hosts.

• Journal of the Korea Society of Computer and Information
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• v.17 no.1
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• pp.141-149
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• 2012

This paper proposes a resource management and allocation algorithm to guarantee QoS continuity of realtime multimedia services and to maximize the resource utilization in heterogeneous wireless networks simultaneously. This scheme reserves the appropriate resources to be used by real-time multimedia services and allocates those resources left unused due to decreased transmission rate of realtime services to non-realtime services. Those resources can be preempted by the need of realtime services later. Performances are analyzed by simulation.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.277-280
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• 1998

As user's demands for high-speed data traffic are recently increased, ABR services are considered as one of important service requirements in ATM networks. Unfortunately, a number of existing ATM switching systems have structural drawbacks as to support ABR services because these switching systems have been developed to support realtime(rt) services such as CBR and rt-VBR services. To support ABR services in the existing ATM switching systems, new traffic control mechanisms for ABR services are required. This paper proposes a method for supporting ABR services in ATM swithcing systems without back-pressure mechanisms and evaluates the performance of the proposed method using simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9A
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• pp.736-745
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• 2003

Resource allocation methods are proposed to address the problem of how flexibly allocate limited wireless resource to high bandwidth demanded realtime class with certain QoS guarantees in CDMA/TDD systems. In this method, A reserved access scheme is used for allocating the resource to realtime and non-realtime class respectively. We also propose a slot allocation algorithm for the CDMA/TDD system, which can prevent the performance degradation due to the interlink interference in each cell. Our framework is able to guarantee QoS continuity of realtime class and carry the maximum number of non-realtime subscriber. System performance of proposed method is evaluated by considering transmission delay, channel utilization and data loss, assuming a practical multi-cell environment and a multimedia service model. Our simulation results demonstrate the significant performance improvement.

• The Journal of the Korea Contents Association
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• v.6 no.2
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• pp.9-16
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• 2006

This paper proposes a scheduling algorithm for efficiently processing multimedia pakcet services in OFDMA physical system of the future broadband wireless access networks. The scheduling algorithm uses wireless channel state estimation, and allocates transmission rates after deciding transmission ordering based on class and priority policy. As the result, the proposed scheduling algorithm offers maximum throughput and minimum jitter for realtime services, and fairness for non-realtime services. In simulation study, the proposed algorithm proves superior performances than traditional round robin method.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.509-512
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• 2003

On-going convergence between broadcasting and communication is currently bringing in lots of drastic changes to multimedia services to the home. The FTTH-based home networks will be the interface among the digital home appliances for broadcast digital contents as weil as for broadband data connection. In this paper, we discuss several design issues for home gateway architecture that effectively distributes realtime broadcasting contents (from either the headend in the access network or the satellite/terrestrial broadcasts) to heterogeneous devices in the home network.

• ETRI Journal
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• v.29 no.2
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• pp.201-211
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• 2007

This paper focuses on the scheduling problem with the objective of maximizing system throughput, while guaranteeing long-term quality of service (QoS) constraints for non-realtime data users and short-term QoS constraints for realtime multimedia users in multiclass service high-speed uplink packet access (HSUPA) systems. After studying the feasible rate region for multiclass service HSUPA systems, we formulate this scheduling problem and propose a multi-constraints HSUPA opportunistic scheduling (MHOS) algorithm to solve this problem. The MHOS algorithm selects the optimal subset of users for transmission at each time slot to maximize system throughput, while guaranteeing the different constraints. The selection is made according to channel condition, feasible rate region, and user weights, which are adjusted by stochastic approximation algorithms to guarantee the different QoS constraints at different time scales. Simulation results show that the proposed MHOS algorithm guarantees QoS constraints, and achieves high system throughput.

• Journal of the Korea Society of Computer and Information
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• v.21 no.1
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• pp.49-57
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• 2016

In this paper we propose the resource allocation scheme for the overlaid macro-femtocell networks, which considers the type of handovers such as the inter-macrocell, macrocell-to-femtocell, femtocell-to-macrocell, or inter-femtocell in order to guarantee Quality of Service (QoS) and expand the accommodation capacity. Our proposed scheme takes into account the movement of mobile terminals, the QoS degradation, or the load control which trigger handovers in the overlaid networks, before it allocates resources dynamically. Moreover it considers QoS requirements of realtime or non-realtime mobile multimedia services such as video communication, Video on Demand (VoD) and dataa services. Simulation results show that our scheme provides better performances than the conventional one with respect to the outage probability, data transmission throughput and handover failure rate.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.6A
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• pp.565-572
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• 2007

3G Long Term Evolution (3G LTE) is a next generation cellular networks system capable or providing various mobile multimedia services by using OFDMA and MIMO based radio access technology. Among many differences from existing WCDMA based systems, the facts that 3G LTE uses Physical Resource Block (PRB) as its radio resources and provides all services through the PS domain make the development of new resource management schemes necessary. This paper proposes an adaptive partitioning based downlink call admission control scheme. It separates realtime call requests from non-realtime ones, specifies maximum allowable resource amounts for each type, but if the maximum is exceeded, call requests are accepted with probability proportional to remaining resource amounts. Despite the fact that such adaptive concept has been already adopted by other call admission schemes, the contributions of our paper, which are that we are able to find an efficient way to apply the proposed scheme exploiting PRB characteristics and measure the resource usage of base stations by PRB utilization and payload ratio, are still valid. When judging from simulation results in comparison with others, our scheme is able to prioritize realtime call requests over non-realtime ones, and at the same time, overall system performance is superior.