• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.9
• /
• pp.1767-1775
• /
• 2015

There are various kinds of applications for wireless sensor network, and each application has difference requirements such as throughput. Topology control is the key issue to minimize energy consumption by solving communication collision and radio interference. However, existing topology control algorithms cannot support application requirement because communication efficiency and network connectivity are the main issues of topology control. In this paper, we propose a topology control algorithm that support throughput requirement of an application.

• The KIPS Transactions:PartA
• /
• v.8A no.2
• /
• pp.157-166
• /
• 2001

A simulation package has been developed as an event-driven system that can handle the hardware configuration of STC104 and algorithm proposed in the sister paper of ‘Study on High Speed Routers(II).’After various STC104 topology of meshes, torus, and hypercubes are constructed using up to 512 switches, the performance of each topology has been analyzed under different message generation rate in terms of throughputs, latency, and packet blocking time. Modified multicast algorithms for STC104 have been proposed for STC104 after U-mesh and U-torus in order to overcome the multicasting difficulty because of the point-to-point communication method found in STC104. The performance of the multicast algorithms have been analyzed over meshes and torus configuration. Throughput gets higher in the order of mesh, torus, and hypercube. Throughput difference among topology were distinctive in the zone of high message generation rate. Latency and blocking time increased in the order of hypercube, torus, and mesh. U-mesh and U-torus of software multicast showed similar throughput, however, U-mesh peformed slightly better result. These algorithms showed eight to ten times better results compared to individual message pass for 90 destination nodes. Multi-link environment also showed better performance than single-link environment because multi-link network used the extra links for communication.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.11
• /
• pp.5455-5475
• /
• 2016

In this article, we model the distributed relay assignment network as a many-to-one matching market with peer effects. We discuss two scenarios for throughput optimization of relay networks: the scenario of aggregate throughput optimization and the scenario of fairness performance optimization. For the first scenario, we propose a Mutual Benefit-based Deferred Acceptance (MBDA) algorithm to increase the aggregate network throughput. For the second scenario, instead of using the alternative matching scheme, a non-substitution matching algorithm (NSA) is designed to solve the fairness problem. The NSA improves the fairness performance. We prove that both two algorithms converge to a globally stable matching, and discuss the practical implementation. Simulation results show that the performance of MBDA algorithm outperforms existing schemes and is almost the same with the optimal solution in terms of aggregate throughput. Meanwhile, the proposed NSA improves fairness as the scale of the relay network expands.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• v.9 no.1
• /
• pp.578-582
• /
• 2005

This paper describes MAC schemes for QoS enhancement taking into account the traffic characteristics and network states over IEEE 802.11 wireless networks. Our approach uses AR as a Backoff parameter and to slide IFS adaptively for increasing the medium utilization ratio and throughput, and providing fairness. In addition, we evaluate through simulations using NS-2 the performance of proposed MAC scheme and compare it with other MAC schemes.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.5
• /
• pp.911-916
• /
• 2016

The nearest-neighbor multihop routing with/without infrastructure support is known to achieve the optimal capacity scaling in a large packet-erasure network in which multiple wireless nodes and relay stations are regularly placed and packets are erased with a certain probability. In this paper, a throughput scaling law is shown for an infrastructure-supported erasure network where wireless nodes are randomly distributed, which is a more feasible scenario. We use an exponential decay model to suitably model an erasure probability. To achieve high throughput in hybrid random erasure networks, the multihop routing via highway using the percolation theory is proposed and the corresponding throughput scaling is derived. As a main result, the proposed percolation highway based routing scheme achieves the same throughput scaling as the nearest-neighbor multihop case in hybrid regular erasure networks. That is, it is shown that no performance loss occurs even when nodes are randomly distributed.

• Journal of KIISE:Information Networking
• /
• v.34 no.6
• /
• pp.505-513
• /
• 2007

Vertical handoff is a new type of handoff in wireless networks. It is issued when a mobile node moves over overlapping wireless networks with each proving a different access bandwidth, transmission latency, and coverage. By issuing the vertical handoff, the mobile node can obtain better network bandwidth. In the sense of TCP throughput, however, the vertical handoff does not always produce positive performance gain, so sometimes it is better for the mobile node to stay at lower bandwidth providing network rather than to select and move to higher bandwidth providing network. In this paper, we analyze TCP throughput for vertical handoff, and propose a new handoff decision scheme which can estimate TCP throughput at the moment of vertical handoff. Based on the estimation, a mobile node can decide to issue vertical handoff to produce better TCP throughput, and we verify the results by simulations.

• Journal of Korea Multimedia Society
• /
• v.10 no.12
• /
• pp.1645-1654
• /
• 2007

In this paper, we study the problem of load balancing routing in clustered-based wireless mesh network in order to enhance the overall network throughput. We first address the problems of cluster allocation in wireless mesh network to achieve load-balancing state. Due to the complexity of the problem, we proposed a simplified algorithm using gradient load-balancing model. This method searches for a localized optimal solution of cluster allocation instead of solving the optimal solution for overall network. To support for load-balancing algorithm and reduce complexity of topology control, we also introduce limited broadcasting between two clusters. This mechanism maintain shortest path between two nodes in adjacent clusters while minimizing the topology broadcasting complexity. The simulation experiments demonstrate that our proposed model achieve performance improvement in terms of network throughput in comparison with other clustering methods.

• International Journal of Computer Science & Network Security
• /
• v.22 no.4
• /
• pp.394-400
• /
• 2022

The radio resources available in a wireless network system are limited. Therefor, job of managing resources is not easy task. Because the resources are shared among the UEs that are connected, the process of assigning resources must be carefully controlled. The packet scheduler in an LTE network is in charge of allocating resources to the user equipment (UE). Femtocells networks are being considered as a promising solution for poor channel performance for mulitple environments. The implementation of femtocells into a macrocell (traditional base station) would boost the capacities of the cellular network. To increase femtocells network capacity, a reliable Packet Scheduler mechanism should be implemented. The Packet Scheduler technique is introduced in this paper to maximize capacity of the network while maintaining fairness among UEs. The proposed solution operates in a manner consistent with this principle. An analysis of the proposed scheme's performance is conducted using a computer simulation. The results reveal that it outperforms the well-known PF scheduler in terms of cell throughput and average throughput of UEs.

• Journal of Korean Institute of Industrial Engineers
• /
• v.32 no.2
• /
• pp.104-110
• /
• 2006

When a new facility such as automobile assembly line is designed, computer simulation is often used to estimate its actual throughput level. If it falls short of the target throughput level, then the design must be modified to increase the throughput capacity. For complex facilities having parallel processes and network of material flows, the modification procedure is not trivial. Even if the capacity of a particular bottleneck process is increased, the target throughput may not be achieved because the bottleneck may move to another process. Furthermore, each process has a different set of options with different cost to increase the capacity. In this study, we present a systematic procedure of determining the cost-effective set of options which achieves the target throughput.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.24 no.2
• /
• pp.65-70
• /
• 2024

In recent years, research on smart factory wireless mobile communication technology that wirelessly remotely controls utilities is being actively conducted. The Wi-SUN (Wireless Smart Utility Network) Alliance proposed a Wi-SUN protocol structure suitable for building a platform such as a smart factory as a new wireless communication standardization standard based on EEE802.15.4g/e. It analyzes the performance of the IEEE802.15.4e Receiver Initiated Transmission(RIT) Mode Media Access Control (MAC) in terms of throughput and latency, and looks at considerations for efficient operation. RIT mode shows that as the check interval becomes longer, delay time and throughput decrease. It was shown that as the traffic load increases, if the RIT check interval is shortened, the delay time can be shortened and throughput can be increased. RIT mode has the advantage of low power consumption and has neutral characteristics between IEEE802.15.4 and CSL mode in terms of delay time and throughput.