• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.956-958
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• 2010

The paper considers MIMO two-way scheme to optimize the end to end capacity in local wireless mesh network. The basic idea is to perform data transmission via intermediate cooperative nodes and cooperative relay therefore higher throughput can be achieved. Each node is equipped with multiple antennas, and has two time slots one for transmission (Tx) and the other is reception (Rx), which are arranged alternatively in the network. In the conventional SISO network, it takes at least four time slots to accomplish the function of two-way relay. Moreover, cooperative technique is used in order to enhance multiplexing of forward and backward streams.

• International Journal of Computer Science & Network Security
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• v.22 no.3
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• pp.1-8
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• 2022

Supporting real-time flows with delay and throughput constraints is an important challenge for future wireless networks. In this paper, we develop an optimal scheduling scheme to optimally choose the packets to transmit. The optimal transmission strategy is based on an observable Markov decision process. The novelty of the work focuses on a priority-based probabilistic packet scheduling strategy for efficient packet transmission. This helps in providing guaranteed services to real time traffic in Heterogeneous Wireless Networks. The proposed scheduling mechanism is able to optimize the desired performance. The proposed scheduler improves the overall end-to-end delay, decreases the packet loss ratio, and reduces blocking probability even in the case of congested network.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.8
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• pp.1770-1785
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• 2013

In this paper, a multi-hop transmission protocol based on parallel communication of secondary users (SUs) is proposed. The primary multi-hop network coexists with a set of SUs by cooperative spectrum sharing. The main optimization target of our protocol is the overall performance of the secondary system with the guarantee of the primary outage performance. The energy consumption of the primary system is reduced by the cooperation of SUs. The aim of the primary source is to communicate with the primary destination via a number of primary relays. SUs may serve as extra decode-and-forward relays for the primary network. When an SU acts as a relay for a primary user (PU), some other SUs that satisfy the condition for parallel communication are selected to simultaneously access the primary spectrum for secondary transmissions. For the proposed protocol, two opportunistic routing strategies are proposed, and a search algorithm to select the SUs for parallel communication is described. The throughput of the SUs and the PU is illustrated. Numerical results demonstrate that the average throughput of the SUs is greatly improved, and the end-to-end throughput of the PU is slightly increased in the proposed protocol when there are more than seven SUs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.9A
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• pp.758-766
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• 2011

Cooperative communications are adopted as a promising solution to achieve high data rate over large areas in the future 40 wireless system and the relay station (RS) is the key concept in cooperative communications. However, most existing works in this area focus only on optimal RS selections. In addition, there are only few works consider another crucial issue: how many relay stations we need to place. Only when the number of relay stations is defined, the relay station selection can be performed well. In this paper we derive a formula which describes the impact of varying number of RS on end-to-end link throughput assuming a clustering scheme which is based on Voronoi tessellation. In addition to mathematical analysis on the feasibility of the formula, we also examine its performance through a set of simulations under the Erceg path loss model. Simulation results verify that the link throughput gain of our proposed scheme is promising.

• Journal of KIISE:Information Networking
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• v.36 no.5
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• pp.456-469
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• 2009

We develop a new wireless link quality metric, ECOT(Estimated Channel Occupancy Time) that enables a high throughput route setup in wireless mesh networks. The key feature of ECOT is to be applicable to diverse mesh network environments where IEEE 802.11 MAC (Medium Access Control) variants are used. We take into account the exact operational features of 802.11 MAC protocols, such as 802.11 DCF(Distributed Coordination Function), 802.11e EDCA(Enhanced Distributed Channel Access) with BACK (Block Acknowledgement), and 802.11n A-MPDU(Aggregate MAC Protocol Data Unit), and derive the integrated link metric based on which a high throughput end-to-end path is established. Through extensive simulation in random-topology settings, we evaluate the performance of proposed link metric and present that ECOT shows 8.5 to 354.4% throughput gain over existing link metrics.

• Journal of IKEEE
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• v.13 no.1
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• pp.94-100
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• 2009

In recent years, the wireless mesh network (WMN) has been an emerging technology to provide Internet access to fixed and mobile wireless devices. The main goal of this paper is the design and simulation of a new MAC protocol based on the multi-path routing information for wireless mesh networks. The information about multiple paths discovered in the network layer is exploited by the MAC layer in order to forward a frame over the best hop out of multiple hop choices. The performance of our approach is compared with conventional 802.11 MAC through the simulation. The results show that our scheme exhibits a significantly better performance rather than conventional 802.11 MAC protocol in terms of packet overhead, end-to-end throughput and delay.

• ETRI Journal
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• v.36 no.3
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• pp.367-373
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• 2014

With high bandwidth, low interference, and low power consumption, optical network-on-chip (ONoC) has emerged as a highly efficient interconnection for the future generation of multicore system on chips. In this paper, we propose a new path-setup method for ONoC to mitigate contentions, such as packets, by recycling the setup packet halfway to the destination. A new, strictly non-blocking $6{\times}6$ optical router is designed to support the new method. The simulation results show the new path-setup method increases the throughput by 52.03%, 41.94%, and 36.47% under uniform, hotspot-I, and hotspot-II traffic patterns, respectively. The end-to-end delay performance is also improved.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.11
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• pp.1045-1050
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• 2012

In this paper, we propose an effective routing protocol that can be particularly applied to SDDC (Sangmyung Direct Digital Controller) BAS. We have used NS (Network Simulator)-2 to simulate the real building for SDDC BAS. The static, session, DV (Distance Vector), and LS (Link State) algorithms are used and the protocols for performance comparison and evaluation are compared with respect to end to end delay, throughput, and routing overhead. The simulation results show that the DV algorithm is effective for SDDC BAS.

• Journal of the Korea Society of Computer and Information
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• v.21 no.7
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• pp.17-22
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• 2016

In this paper we propose a novel QoE control scheme based on Service Level Agreement (SLA) which enables to guarantee the user perceived service quality of various high-quality mobile multimedia services such as mobile video streaming and real-time network games to a certain level. For this purpose, a SLA control structure is adopted to provision QoE, and a novel resource management scheme gets coupled with this control structure. Simulation results show that our proposed scheme can decrease the average delay and increase the total throughput by adjusting SLA.

• International Journal of Computer Science & Network Security
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• v.22 no.7
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• pp.240-244
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• 2022

The common goals of designing a routing algorithm are not only to reduce control packet overhead, maximize throughput and minimize the end-to-end delay, but also take into consideration the energy consumption. Scalability is an important factor in designing an efficient routing protocol for wireless sensor networks (WSN's). Three metrics (power consumption, time of transmission and packet loss rate) are used in order to compare three routing protocols which are AODV, DSDV and LEACH.