• Journal of Communications and Networks
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• v.14 no.1
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• pp.40-50
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• 2012

The Berkeley-medium access control (B-MAC) is a lightweight, configurable and asynchronous duty cycle medium access control (MAC) protocol in wireless sensor networks. This article presents an analytic modelling of single-hop B-MAC protocol under a Poisson traffic assumption.Our model considers important B-MAC parameters such as the sleep cycle, the two stage backoff mechanism, and the extended preamble. The service delay of an arriving packet and the energy consumption are calculated by an iterative method. The simulation results verify that the proposed analytic model can accurately estimate the performance of single-hop B-MAC with different operating environments.

• Journal of information and communication convergence engineering
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• v.15 no.1
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• pp.28-36
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• 2017

The medium access control (MAC) protocol based on dynamic time division multiple access/time division duplex (TDMA/TDD) is responsible for random access control and radio resource allocation in dynamic traffic environments. These functions of random access and resource allocation are very important to prevent wastage of resources and improve MAC performance according to various network conditions. In this paper, we propose new random access and resource allocation schemes to guarantee quality of service (QoS) and provide priority services in a dynamic TDMA/TDD system. First, for the QoS guarantee, we propose an adaptive random access and resource allocation scheme by introducing an access probability. Second, for providing priority service, we propose a priority-based random access and resource allocation scheme by extending the first adaptive scheme in both a centralized and a distributed manner. The analysis and simulation results show that the proposed MAC protocol outperforms the legacy MAC protocol using a simple binary exponential backoff algorithm, and provides good differential performance according to priorities with respect to the throughput and delay.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.569-572
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• 2003

The broadband wireless access industry, which provides high-tate network connections to stationary sites, has matured to the point at which it now has a standard for second-generation wireless metropolitan area networks. IEEE Standard 802.16, with its WirelessMAN air interface, set the stage for widespread and effective deployments worldwide. This paper presents an implementation of media access control that can be applied to BWA (Broadband Wireless Access) system. Medium access control (MAC) is a key issue in multi-access networks where a common channel is shared by many users. The designed MAC prototype roughly consists of MAC Hardware and MAC Software. The MAC Hardware part includes timing process, MAC transmission control, MAC reception control, and CRC/HCS process. The MAC Software part includes control of MAC signaling, network interface, and Physical (PHY) control. The designed MAC protocol will be integrated with the PHY of BWA in future and we can test overall system performance of MAC and PHY.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.517-520
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• 2005

Wireless sensor network combines sensing and computing technology which can sense light, temperature, vibration, magnetic field and wind etc, as each purpose of using those. Wireless nodes operate signal processing skill which has proceeded sensed information from the sensor, transmission which makes information reached to observer and limited energy managing skill which is needed on account of using battery to operate wireless. To make responsible measuring and sensing out of them, efficient energy management is so important to maintain life time of network. In this paper, after explaining CSMA/CA(Carrier Sense Multiple Access/Collision Avoidance) traditional wireless MAC protocol, and ER-MAC(Energy Rate Medium Access Control) which are not managing resource of hardware but MAN(Medium Access Control), data-link layer out of OSI 7 layer. We would like to analyze those efficiency of power saving comparing with each protocol.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.3
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• pp.31-36
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• 2007

This paper proposes Co-MAC (Coexistence MAC), an energy efficient medium access control protocol designed for large-scale sensor networks. In Co-MAC protocol, an overall network is divided into independent subnets, and each subnet orthogonally operates on time line in a temporal fashion. The basic idea of Co-MAC is to evenly distribute sensor nodes in a certain geographic area based on subnets to minimize overhearing which means the reception of unnecessary data packets from neighboring nodes. In our simulation, it was observed that energy efficiency of Co-MAC outperforms conventional MAC protocols under the given conditions.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.423-425
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• 2007

In this paper, Medium Access Control(MAC) protocol designed for Wireless Body area Sensor Network(Bio-MAC) is proposed, Because in WBSN, the number of node is limited and each node has different characteristics. Also, reliability in transmitting vital data sensed at each node and periodic transmission should be considered so that general MAC protocol cannot satisfy such requirements of biomedical sensors in WBSN. Bio-MAC aims at optimal MAC protocol in WBSN. For this, Bio-MAC used Pattern -SuperFrame, which modified IEE E 802.15.4-based SuperFrame structurely. Bio-MAC based on TDMA uses Medium Access-priority and Pattern eXchange -Beacon method for dynamic slot allocation by considering critical sensing data or power consumption level of sensor no de etc. Also, because of the least delay time. Bio-MAC is suitable in the periodic transmission of vital signal data. The simulation results demonstrate that a efficient performance in WBSN can be achieved through the proposed Bio-MAC.

• Journal of Communications and Networks
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• v.6 no.4
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• pp.317-330
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• 2004

In this paper, we explore the utility of recently discovered multiple-antenna techniques (namely MIMO techniques) for medium access control (MAC) design and routing in mobile ad hoc networks. Specifically, we focus on ad hoc networks where the spatial diversity technique is used to combat fading and achieve robustness in the presence of user mobility. We first examine the impact of spatial diversity on the MAC design, and devise a MIMO MAC protocol accordingly. We then develop analytical methods to characterize the corresponding saturation throughput for MIMO multi-hop networks. Building on the throughout analysis, we study the impact of MIMO MAC on routing. We characterize the optimal hop distance that minimizes the end-to-end delay in a large network. For completeness, we also study MAC design using directional antennas for the case where the channel has a strong line of sight (LOS) component. Our results show that the spatial diversity technique and the directional antenna technique can enhance the performance of mobile ad hoc networks significantly.

• KIISE Transactions on Computing Practices
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• v.22 no.8
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• pp.381-386
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• 2016

Recently full-duplex communication in wireless networks is enabled by the advancement of self-interference cancellation technology. Full-duplex radio is a promising technology for next-generation wireless local area networks (WLAN) because it can simultaneously transmit and receive signals within the same frequency band. Since legacy medium access control (MAC) protocols are designed based on half-duplex communication, they are not suitable for full-duplex communication. In this paper, we discuss considerations of full-duplex communication and propose a novel full-duplex MAC protocol. We conducted a simulation to measure the throughput of our MAC protocol. Through the simulation results, we can verify that significant throughput gains of the proposed full-duplex MAC protocol, thus comparing the basic full-duplex MAC protocol.

• Journal of Communications and Networks
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• v.17 no.3
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• pp.247-255
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• 2015

In this paper, we propose an adaptive time division multiple access based medium access control (MAC) protocol, called bitmap-assisted shortest job first based MAC (BS-MAC), for hierarchical wireless sensor networks (WSNs). The main contribution of BS-MAC is that: (a) It uses small size time slots. (b) The number of those time slots is more than the number of member nodes. (c) Shortest job first (SJF) algorithm to schedule time slots. (d) Short node address (1 byte) to identify members nodes. First two contributions of BS-MAC handle adaptive traffic loads of all members in an efficient manner. The SJF algorithm reduces node's job completion time and to minimize the average packet delay of nodes. The short node address reduces the control overhead and makes the proposed scheme an energy efficient. The simulation results verify that the proposed BS-MAC transmits more data with less delay and energy consumption compared to the existing MAC protocols.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2465-2472
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• 2015

Wireless Medium Access Control (MAC) and routing technologies are the basic building blocks making it possible the Internet of Things (IoT). These technologies have been the focus of substantial research in the last decade. Nevertheless, as new networking standards for IoT are being proposed and different solutions are patched together, evaluating the performance of the network becomes unclear. In this paper, a new overview of MAC and routing protocols for IoT and new interactions are given. The IEEE 802.15.4 MAC and Routing Protocol for Low-power Lossy Network (RPL) routing protocols are taken as reference to exemplify and illustrate the discussion. Experimental results show that contention-based access MACs may hurt the routing, unless these two are carefully designed together.