• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.4760-4765
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• 2010

Time out-medium access control (T-MAC) protocol is one of the well-known MAC protocols designed for wireless sensor networks (WSN), and is proposed to enhance the poor performance of the S-MAC protocol. In this paper, we are reviewed about security vulnerability in T-MAC, and analyzed the power which is consumed at each stage of T-MAC protocol according to vulnerability of denial of service (DoS) and replay problem. From our analytical results, it can be considered the need of power efficient authentication scheme which provides the reliability, efficiency, and security for a general T-MAC communication. This is the case study of possible DoS vulnerability and its power consumption in T-MAC.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.99-103
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• 2006

In this paper, we focus on the problem of designing an energy efficient MAC protocol for wireless sensor networks and analyze S(Sensor)-MAC and T(Time-out)-MAC. S-MAC is based on the concept of the 'listen/sleep mode cycle'. This applies message passing to reduce contention latency for sensor-network applications that require store-and-forward processing as data moves through the network. However unlike the S-MAC, where the duration of the cycle is fixed, T-MAC introduces an adaptive duty cycle in a novel way: by dynamical ending the active part of it. This reduces the amount of energy wasted on idle listening, in which nodes wait for potentially incoming messages while still maintaining a reasonable throughput. In this paper we discuss the design of these two Protocols. We analyze them from the aspect of latency, throughput, and power savings when using the OMNeT++ simulator in various environments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11A
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• pp.1138-1146
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• 2006

It is very important for the sensor network to save battery capacity. Switching active mode to sleep mode is used for S-MAC protocol and expiring timer before end of the active part is used for T-MAC in order to extend battery life span. We proposed IS-MAC (Improved Sensor MAC) which gives more energy efficiency than S-MAC and T-MAC To improve energy efficiency in sensor network, we used the threshold value in buffer to transmit data packet and proposed the method to reduce the number of control packets which cause extra battery consumption. Based on the analytical results, we found that the proposed IS-MAC protocol shows better performance than conventional MAC protocols.

• Proceedings of the KAIS Fall Conference
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• 2010.05a
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• pp.166-168
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• 2010

본 논문에서는 TMAC 환경에서 취약성 분석하였다. T-MAC의 보안 특성은 S-MAC 통신 프로토콜이 갖는 보안 취약성과 동일한 형태이다. T-MAC 통신은 TA가 도입된 것을 제외하면, S-MAC에서 강조하고 있는 동일한 보안 인증방안이 필요함을 확인할 수 있다.

• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.613-619
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• 2020

Hybrid media access control (MAC) is used in internet of things (IoT) network, because of communication feature concern with data capacity and communication interval between gateway and sensor nodes and the cost efficiency. Hybrid MAC consists of TDMA and CSMA generally. The distance between gateway and sensor node is openly changed in marine IoT network. Therefore, it is needed to control the period of timeslot of hybrid MAC used in marine IoT network. In this paper, the design rule of TDMA timeslot with the variable period depending on communication distance was proposed. It was confirmed from the analysis that 72 times communication between gateway and sensor nodes is possible in LoRa network by using the proposed TDMA variable timeslot scheme.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.6
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• pp.97-103
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• 2008

T-Lohi, a MAC protocol for underwater acoustic sensor networks, has been designed to support dense networks consisting of short-range acoustic modems. However when T-Lohi is applied to large networks in which multi-hop routing is necessary, it suffers a lot of packet collisions due to the hidden terminal problem. To combat this problem, we propose a new MAC protocol which employs RTS/CTS handshaking. To our knowledge, this protocol is the first to adopt both a tone-based approach and RTS/CTS handshaking for dense underwater acoustic sensor networks. Simulation results show that this new protocol drastically reduces packet collisions while achieving good network utilization.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.890-893
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• 2010

In wireless sensor networks, each node generally uses a battery because it is hard to replace or charge. For this reason, study for life time prolongation of each node within the limited energy source has become an important issue. So many ways are suggested to minimize the energy consumption for each node, especially energy efficient MAC protocols have been studied actively. T-MAC of contention based MAC protocol is that added the adaptability on fixed duty cycle of S-MAC. T-MAC allocates the fixed timeout before each node goes to sleep mode from active mode. If no data exchanged in a timeout, each node goes to sleep mode. Because of the timeout is always fixed, the absence of data exchange in a timeout will cause unnecessary energy consumption. In this paper, in order to improve the energy efficiency, we propose a MAC protocol based on adaptive timeout that analyze the probability of the timeout, and provides the modified timeout.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.07a
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• pp.361-364
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• 2014

무선 센서 네트워크를 구성하는 각 센서 노드들은 한정된 전력의 배터리로 동작하므로, 센서 네트워크에서의 에너지 효율성은 중요한 이슈이다. 따라서, 센서 노드의 에너지 소모를 줄여서 전체 네트워크 수명을 최대화하기 위해 MAC 계층에서의 다양한 프로토콜이 제안되었다. 본 논문에서는 센서 네트워크의 에너지 효율성을 향상시키기 위한 에너지 효율적인 CA-MAC(Context Adaptive MAC) 프로토콜을 제안한다. 제안된 CA-MAC 프로토콜은 데이터의 전송 여부를 결정하는 각 버퍼 임계값을 싱크와 노드의 거리에 따라 차등적으로 설정함으로써 노드의 에너지 소비를 감소시켜 전체 네트워크의 에너지 효율성을 크게 향상 시킨다. 또한, 전송 지연 시간을 감소시키기 위하여 센싱된 데이터의 긴급 여부에 따른 전송을 수행한다. 본 논문의 성능 평가는 OMNeT++을 이용한 모의실험을 통해 진행하였으며, 그 결과 기존에 제안되었던 S-MAC 및 T-MAC 프로토콜과 비교하여 제안된 기법이 데이터 전송 시간과 에너지 효율성을 향상시키고 네트워크 수명을 연장하였음을 확인하였다.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.633-633
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• 2006

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1646-1652
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• 2010

The communication in wireless sensor network is divided into several layers, because of each of them do their role, the wireless communication is possible, the MAC (Medium Access Control) layer of the one of sensor network communications layer is used to the data errors, control flow, and manage resources. Using MAC Protocol, it ensures the communication between sensor node. In this paper, highlighted the energy efficiency of the S-MAC, T-MAC protocol it emphasized the efficiency of energy by lessening the woken time of all nods effectively, transmitting and receiving the control packet on only necessary nods through use of a method that RTS packet is added to SYNC packet and making other nods sleep. On sending SYNC+RTS packet and receiving the packet, nod noticed that it wasn't necessary to be awaked on this period, would be in Sleep mode, demonstrated mathematically that energy is more effective than existing protocol, and simulated with MATLAB.