• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.6
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• pp.225-236
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• 2003

In this paper, we propose a wireless scheduling algorithm to provide the Internet delay proportional differentiated services in wireless networks. For considering network environments that have burst and location-dependent channel errors, our proposed WDPS(Wireless Delay Proportional Service) scheduling algorithm adaptively serves packets in class queues based on the delivered delay performance for each class. The remarkable characteristics of WDPS scheduler are supporting a fair relative delay service, providing graceful throughput and delay compensation, and avoiding class queue blocking problem. Through simulations, we show that the algorithm achieves the desirable properties to provide delay proportional services in wireless networks.

• Journal of Communications and Networks
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• v.13 no.2
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• pp.160-166
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• 2011

In u-healthcare services based on wireless body sensor networks, reliable connection is very important as many types of information, including vital signals, are transmitted through the networks. The transmit power requirements are very stringent in the case of in-body networks for implant communication. Furthermore, the wireless link in an in-body environment has a high degree of path loss (e.g., the path loss exponent is around 6.2 for deep tissue). Because of such inherently bad settings of the communication nodes, a multi-hop network topology is preferred in order to meet the transmit power requirements and to increase the battery lifetime of sensor nodes. This will ensure that the live body of a patient receiving the healthcare service has a reduced level of specific absorption ratio (SAR) when exposed to long-lasting radiation. We propose an efficientmethod for delivering delay-intolerant data packets over multiple hops. We consider forward error correction (FEC) in an erasure correction mode and develop a mathematical formulation for packet-level scheduling of delay-intolerant FEC packets over multiple hops. The proposed method can be used as a simple guideline for applications to setting up a topology for a medical body sensor network of each individual patient, which is connected to a remote server for u-healthcare service applications.

• The KIPS Transactions:PartC
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• v.11C no.6 s.95
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• pp.863-870
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• 2004

UMTS(Universal Mobile Telecommunication System) is recently recognized as a standard for 3rd generation of wireless networks and DSCH(Down-link Shared Chanel) is considered as a very effective multiplexing method in UMTS. So, it is inevitable to develope an effective packet scheduling algorithms for DSCH in UMTS. This paper describes an improved packet scheduling algorithm for DSCH of UMTS. The algorithm takes consideration in channel state for each mobile terminal to maximize link utilization, delay threshold for class 3 traffic and throughput for class 4 to get long term fairness. To verify the algorithm, we programmed a simulator using PARSEC simulation tool and got some simulation results by it. The simulation results show that the algorithm has reasonable characteristics in both of link utilization and fair-ness by trade-off.

• The Journal of the Korea Contents Association
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• v.7 no.10
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• pp.1-9
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• 2007

Allocation and management of the resource is very important in wireless networks because the wireless resource is limited. Therefore, the importance of designing cross layer, which adapt between different layers, is on the rise. In this paper, we investigate the scheduling techniques of the cross layer. This paper researches conventional scheduling methods and proposes the complementary scheduling method. On multimedia environment, the scheduling method must be applied variably because of offering variable services. Therefore, this paper proposes the new scheduling method according to the variable services. The proposed method shows that utility efficiency of the wireless resource more excellent than the conventional method through the simulations.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.12
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• pp.99-108
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• 2014

WBAN(Wireless Body Area Network) is network to support medical and non-medical services. It is susceptible to loss and delay of data. WBAN is required to satisfy many kinds of demands such as a variety of data rate and a data priority for providing various service. In this paper scheduling algorithm, considering a data priority and transmission delay time, is proposed to improve service quality of WBAN. The proposed algorithm operates by allocating a channel to a flow with longer transmission delay. When a packet, in a queue of herb, is left within a certain period, the packet is assigned a channel and transmitted according to a data priority. Through the comparison with other existing scheduling algorithms, it is confirmed that QoS is improved due to higher arrival probability of medical data and less delay time in the proposed algorithm.

• Journal of Information Processing Systems
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• v.7 no.2
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• pp.261-270
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• 2011

The IEEE 802.16 standard is supposed to provide a wide-range broadband wireless service, but it leaves the implementation of the wireless resource scheduler as an open issue. We have studied the scheduling problem and propose a two level scheduling (TLS) scheme with support for quality of service and fairness guarantees for downlink traffic in a WiMAX network. A central controller Base Station has a number of users, and each mobile subscriber station has different channel conditions. The same mobile subscriber station may have different service requirements at different times in the WiMAX network. Based on OPNET simulation, the results show our scheduling algorithm can increase the network throughput, maintain relative fairness, and lower delay over the round robin and weighted round robin algorithms.

• Journal of the Semiconductor & Display Technology
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• v.12 no.4
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• pp.1-7
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• 2013

This paper presents the AMR (Automatic Meter Reading) system using the binary CDMA (Code Division Multiple Access) radio technology. The binary CDMA is the new radio technology in domestic research. Main implementation topics includes the binary CDMA remote meter reading system, the wireless piconet configuration for the wireless automatic meter reading, and the transmission scheduling for sending and receiving data. Also, the wireless packet data encryption is very important topics for the wireless automatic meter reading. The proposed AMR system is implemented as a pilot project in Jeju and Gangwon. It can be seen that the wireless remote reading using the binary CDMA wireless technology can be applied to the AMR system.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2406-2412
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• 2015

Multi-user multi-input multi-output (MU-MIMO) system has attracted the 4^th generation wireless network as one of core technique for performance enrichment. In this system rate control is a challenging problem and another problem is optimization. Proper scheduling can resolve these problems by deciding which set of user and at which rate the users send their data. This paper proposes a new multi-parameter based scheduling (MPS) for downlink multi-user multiple-input multiple-output (MU-MIMO) system under space-time block coding (STBC) transmissions. Goal of this MPS scheme is to offer improved link level performance in terms of a low average bit error rate (BER), high packet delivery ratio (PDR) with improved resource utilization and service fairness among the user. This scheme allows the set of users to send data based on their channel quality and their demand rates. Simulation compares the MPS performance with other scheduling scheme such as fair scheduling (FS), normalized priority scheduling (NPS) and threshold based fair scheduling (TFS). The results obtained prove that MPS has significant improvement in average BER performance with improved resource utilization and fairness as compared to the other scheduling scheme.

• The KIPS Transactions:PartA
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• v.14A no.4
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• pp.197-202
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• 2007

This study focused on design and implementation of Mobile 3D Bluetooth Game Engine based on OpenGL-ES. In Mobile 3D network game so far, there is a form the mainstream of wireless inter-net game using WAP and VM. But, VM game we popular because of an excessive communication expense problem for this mobile network game that occur when connect to wireless internet as point out to problem by it, that is, stand-alone game are very popular. This study introduce a mobile 3D Bluetooth Game Engine which is based on mobile 3D standard using OpenGL-ES to solve a problem like mobile network game generally that occur when connect to take pleasure a wireless internet from some people into a short distance. When the number of concurrent packet datum by Bluetooth terminal transfers to each other, we shows that the proposed scheduling scheme for enhancing the process speed up on Bluetooth.

• Journal of Communications and Networks
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• v.18 no.5
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• pp.846-856
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• 2016

Wireless sensor networks (WSNs) are widely applied in monitoring and control of environment parameters. It is sometimes necessary to disseminate data through wireless links after they are deployed in order to adjust configuration parameters of sensors or distribute management commands and queries to sensors. Several approaches have been proposed recently for data dissemination in WSNs. However, none of these approaches achieves both high efficiency and low complexity simultaneously. To address this problem, cluster-tree based network architecture, which divides a WSN into hierarchies and clusters is proposed. Upon this architecture, data is delivered from base station to all sensors in clusters hierarchy by hierarchy. In each cluster, father broadcasts data to all his children with instantly decodable network coding (IDNC), and a novel scheme targeting to maximize total transmission gain (MTTG) is proposed. This scheme employs a new packet scheduling algorithm to select IDNC packets, which uses weight status feedback matrix (WSFM) directly. Analysis and simulation results indicate that the transmission efficiency approximate to the best existing approach maximum weight clique, but with much lower computational overhead. Hence, the energy efficiency achieves both in data transmission and processing.