• ETRI Journal
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• v.29 no.1
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• pp.120-123
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• 2007

In this letter, we address the problem of resource allocation with efficiency and quality of service (QoS) support in uplink for a wireless CDMA network supporting real-time (RT) and non-realtime (NRT) communication services. For RT and NRT users, there are different QoS requirements. We introduce and describe a new scheme, namely, traffic aided uplink opportunistic scheduling (TAUOS). While guaranteeing the different QoS requirements, TAUOS exploits the channel condition to improve system throughput. In TAUOS, the cross-layer information, file size information, is used to improve fairness for NRT users. Extensive simulation results show that our scheme can achieve high system throughput in uplink wireless CDMA systems, while guaranteeing QoS requirements.

• Journal of Korea Multimedia Society
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• v.11 no.12
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• pp.1730-1738
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• 2008

Quality of Service (QoS) Guarantees grant ways for service providers to establish service differentiation among subscribers. On the other hand, service subscribers are also assured the level of service they paid for. In addition, the efficient level of service quality can be selected according to the subscribers' needs thus ensuring efficient use of available bandwidth. While network utility optimization techniques assure certain QoS metrics, a number of situations exist where some QoS goals are not met. The optimality of the network parameters is not mandatory to guarantee specified QoS levels. This paper proposes a joint data rate and power control scheme that guarantees service contract QoS level to a subscriber using Goal Programming. In using goal programming, this paper focuses on finding the range of feasible solutions as opposed to solving for the optimal. In addition, in case no feasible solution is found, an acceptable compromised solution is solved.

• Journal of Korea Multimedia Society
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• v.15 no.12
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• pp.1464-1474
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• 2012

In this paper, we propose a QoS (Quality of Service)-aware and cooperative resource reservation scheme using cross-layer link adaptation for wireless high definition video transmission through UWB (Ultra Wide Band) network with D-MAC (Distributed Medium Access Control). A wireless high definition video transmission system usually requires stable high throughput even without line-of-sight, e.g., a destination device in another room separated by a wall. Since the WiMedia D-MAC supporting DRP (Distributed Reservation Protocol) scheme causes lots of DRP resource reservation conflicts due to failure of beacon detection in wireless channel environment, overall performances of the WiMedia D-MAC can be deteriorated. And the current WiMedia MAC standard has not considered QoS provisioning even though QoS parameters such as a range of service rates are provided to each traffic stream. Therefore, we propose Relay DRP protocol with QoS-based relay node selection criterion, which makes a relay path to avoid DRP resource reservation conflicts and guarantee QoS more stably through cross-layer link adaptation of cooperative relay transmission scheme and is compliant with the current WiMedia D-MAC protocol. Simulation results demonstrate performance improvements of the proposed method for throughput and QoS provisioning.

• Journal of Advanced Navigation Technology
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• v.16 no.3
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• pp.463-470
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• 2012

This paper proposes a new profit popularity-based segment caching control mechanism for assuring a consecutive streaming QoS (Quality of Service) in the wireless channel. Then, the proposed mechanism operates SSCP (Single Segment Caching Profit) and MSCP (Multiple Segment Caching Profit) for assuring a QoS. SSCP and MSCP is to optimize the cache performance when is performed the streaming in the proxy. The proposed mechanism simulated to evaluate such mechanisms as fixed-partition mechanism, weight-based mechanism, SSCP, and MSCP. Simulation results show that the proposed mechanism has superior performance compared to other mechanisms.

• Journal of Communications and Networks
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• v.11 no.4
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• pp.390-405
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• 2009

Wireless sensor networks (WSNs) are envisioned to facilitate information gathering for various applications and depending on the application types they may require certain quality of service (QoS) guarantee for successful and guaranteed event perception. Therefore, QoS in WSNs is an important issue and two most important parameters that hinder the goal of guaranteed event perception are time-sensitive and reliable delivery of gathered information, while a minimum energy consumption is desired. In this paper, we propose an energy-aware, multi-constrained and multipath QoS provisioning mechanism for WSNs based on optimization approach. Hence, a detailed analytical analysis of reliability, delay and energy consumption is presented to formulate the optimization problem in an analytical way. A greedy algorithm is proposed to achieve the desired QoS guarantee while keeping the energy consumption minimum. Also, a simple but efficient retransmission mechanism is proposed to enhance the reliability further, while keeping the delay within delay bound. Simulation results demonstrate the effectiveness of our scheme.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.5
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• pp.525-532
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• 2004

In this paper, we proposed a multicast routing algorithm for QoS improvement in the wire/wireless integrated environment. We analyzed requests and characteristics of QoS, and then proposed a new algorithm that can improve QoS by adding node mobility to wire environment. This new algorithm constructs a dynamic multicast tree that can prevent a loss of packet and save the bandwidth. As a result of simulations comparing to another multicast algorithms, we showed that this new algorithm can simply and dynamically adjusts the construction of multicast tree with little delay and the most reducible bandwidth resources.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.6A
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• pp.351-360
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• 2003

To provide good-quality services of multimedia in wireless mobile networks, QoS for multimedia traffic should be guaranteed. However, since the existing QoS guaranteed schemes are designed for fixed networks, they are inadequate in the wireless network environments. Recently, as the size of cells like micro cell or pico cell becomes smaller. Mobile hosts on micro cellular networks, change their location frequently. It causes many drawbacks such as delayed delivery, packet losses and signaling overheads. Because the existing schemes supporting interoperability between RSVP and Mobile If are designed for macro cell environments. Their uses in micro cellular networks can be restricted. In this paper, we propose the CRSVP(Cellular RSVP Protocol) which supports QoS in micro cellular network environments.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.3
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• pp.317-324
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• 2016

WiMedia provides the data rate of up to 1Gbps, but the transmission range is restricted to approximately 10 meters. When constructing a multi-hop WiMedia network to extend its coverage, conventional hop-based routing may not guarantee satisfactorily the required QoS. We propose two QoS routing techniques for the WiMedia-based wireless mesh network. The proopsed QoS routing reflects the characteristics of TDMA-based WiMedia MAC and develops QoS extensions separately for on-demand routing and table-driven routing. Through simulations, we identify that the QoS routing shows better performance than the hop-based routing. It also turns out that the QoS on-demand routing and the QoS table-driven routing show conflicting performance results depending on the transmission power.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.11B
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• pp.968-980
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• 2008

Providing handover with guaranteed QoS for real-time multimedia service such as VoIP, video/audio streaming, and video conferencing in wireless LAN is a challenging task. In this paper, we present efficient layer 2 handover mechanism in wireless LAN, which can provide fast handover with guaranteed QoS for real-time multimedia service. To this end, the scanning period and the number of channels per scanning for handover are dynamically adapted to the type of applications and wireless networking environment, so that both the degradation of application service quality and signaling overhead are minimized simultaneously. The performance of the proposed mechanism is verified by the simulation. The simulation results show that the proposed mechanism guarantess QoS of each multimedia application with minimal power consumption.

• IEIE Transactions on Smart Processing and Computing
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• v.1 no.3
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• pp.182-191
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• 2012

This paper proposes a high performance QoS (Quality of Service) traffic transmission scheme to provide real-time multimedia services in wireless networks. This scheme is based on both a traffic estimation of the mean rate and a header compression method by dividing this network model into two parts, core RTP/UDP/IP network and wireless access parts, using the IEEE 802.11 WLAN. The improvement achieved by the scheme means that it can be designed to include a means of provisioning the high performance QoS strategy according to the requirements of each particular traffic flow by adapting the header compression for real-time multimedia data. A performance evaluation was carried out to show the effectiveness of the proposed traffic transmission scheme.