• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.2
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• pp.75-80
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• 2020

There are so many low power MAC protocols for wireless sensor network. IEEE802.15.4 among them has disadvantage of a large power consumption for synchronization. To save power consumption it use the superframe operation alternating sleep mode and awake mode. But latency is longer result from superframe operation. B-MAC can have shorter latency according to check interval. But transmitter consumes more power because of long preamble. And receiver is suffering from overhearing. In this paper, we use the adaptive check interval scheme[1] of B-MAC for enhancing the power consumption. Its maximum throughput and minimum delay is evaluated by comparing the proposed scheme with a typical single channel IEEE802.15.4.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.4
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• pp.369-373
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• 1989

This paper investigates average access times on eight asynchronous priority levels of FDDI MAC protocol with parameters on offered loads, message sizes, and number of stations. In case of parameter with offered loads, higher priority levels exhibit similar variances and in case of parameter with message sizes and number of satations, higher priority levels exhibit almost invariables but as increase of message sizes, increase only a small amount of access time on the other hand, as number of stations increase, average access times decrease little by little. But in case of lowest priority level. average access times decrease little by little. But in case of lowest priority level, average access times exhibit relatively large variances about above three parameters.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.8B
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• pp.712-721
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• 2012

In this paper, we propose an Enhanced cross-layer Geographic Forwarding (EGF) protocol for wireless sensor networks (WSNs). EGF uses an optimal back-off time to make the packet forwarding decisions using only source and destination's location information and energy cost without information about neighbor nodes' location or the number of one hop neighbor nodes. EGF is also a cross-layer protocol by combining efficient asynchronous MAC and geographic routing protocol. The proposed protocol can find optimal next hop location quickly without broadcasting node's location update and with minimizing overhead. In our performance evaluation, EGF has better performance in terms of packet success ratio, energy efficiency and end-to-end delay in wireless sensor networks.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.3
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• pp.23-28
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• 2021

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 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 CSL(Coordinated Sampled Listening) Mode MAC(Media Access Control) in terms of latency and looks at considerations for efficient operation.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.232-234
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• 2004

Ad hoc network는 무선 네트워크 환경에서 에서 AP(Access Point)와 같은 infrastructure없이 STA(Station)들끼리 통신이 가능한 형태의 network이다. Ad hoc network에서는 전력 관리가 중요한 문제들 가운데 하나인데 표준에서는 동기식 전력 관리에 관하여서만 정의하고 있다. 동기식 전력 관리의 경우에는 STA들 사이에 동기가 맞아야 잘 동작한다는 점과 이러한 동기화를 위한 기술적 어려움 그리고 STA들 사이에 독립적인 전력관리가 불가능하다는 점을 단점으로 가지게 된다. 이러한 점을 해결하기 위하여 일반적인 비동기식 전력 관리 방법을 적용시키게 되면 energy saving 측면에서는 효율적이지만 throughput이 현저하게 감소하게 되는 문제가 발생하게 되는데 본 논문에서는 이러한 정을 해결하기 위하여 새로운 비동기식 전력 관리 프로토콜을 제안한다.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.458-458
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• 2004

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.90-93
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• 2016

본 논문에서는 Sub-GHz band module을 Drone에 탑재하여 Drone과 전원공유로 Node(Drone)간 Low power and Long range Ad-hoc communication을 할 수 있는 방법을 제안하고자 한다. 또한 이동성이 있는 Node(Drone)의 Low power and Long range communication을 위해서 Drone에 적합한 Asynchronous MAC (medium access control) protocol을 비교분석하여 적용하였다. 본 고에서는 무선 센서 네트워크의 응용 범위가 확대되면서 고정된 인프라 없이 Drone간에 실시간 정보를 통신 할 수 있게 하고 사람의 이동이 어렵고 위험한 재난지역, 방사선노출지역 또는 우천시 유인기와 사람의 접근이 불가능한 지역을 Drone이 대신 이동하여 인명피해를 줄이고 안전하게 필요한 데이터를 수집하여 상황관제실로 전송하는 서비스를 제공하고자 한다.

• ETRI Journal
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• v.37 no.3
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• pp.480-490
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• 2015

The reliability of sensor networks is generally dependent on the battery power of the sensor nodes that it employs; hence it is crucial for the sensor nodes to efficiently use their battery resources. This research paper presents a method to increase the reliability of sensor nodes by constructing a connected dominating tree (CDT), which is a subnetwork of wireless sensor networks. It detects the minimum number of dominatees, dominators, forwarder sensor nodes, and aggregates, as well as transmitting data to the sink. A new medium access control (MAC) protocol, called Homogenous Quorum-Based Medium Access Control (HQMAC), is also introduced, which is an adaptive, homogenous, asynchronous quorum-based MAC protocol. In this protocol, certain sensor nodes belonging to a network will be allowed to tune their wake-up and sleep intervals, based on their own traffic load. A new quorum system, named BiQuorum, is used by HQMAC to provide a low duty cycle, low network sensibility, and a high number of rendezvous points when compared with other quorum systems such as grid and dygrid. Both the theoretical results and the simulation results proved that the proposed HQMAC (when applied to a CDT) facilitates low transmission latency, high delivery ratio, and low energy consumption, thus extending the lifetime of the network it serves.

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

• Journal of KIISE:Information Networking
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• v.33 no.1
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• pp.16-27
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• 2006

The wireless transmission medium inherently broadcasts a signal to all neighbor nodes in the transmission range. Existing asynchronous MAC protocols do not provide a concrete solution for reliable broadcast in link layer. This mainly comes from that an omni-directional broadcasting causes to reduce the network performance due to the explosive collisions and contentions. This paper proposes a reliable broadcast protocol in link taller based on directional antennas, named MDB(MAC protocol for Directional Broadcasting). This protocol makes use of DAST(Directional Antennas Statement Table) information and D-MACA(Directional Multiple Access and Collision Avoidance) scheme through 4-way handshake to resolve the many collision problem wit]1 omni-directional antenna. To analyze its performance, MDB protocol is compared with IEEE 802.11 DCF protocol [9] and the protocol 2 of reference [3], in terms of the success rate of broadcast and the collision rate. As a result of performance analysis through simulation, it was confirmed that the collision rate of the MDB protocol is lower than those of IEEE 802.11 and the protocol 2 of reference [3], and that the completion rate of broadcast of MDB protocol is higher than those of IEEE 802.11 and the protocol 2 of reference [3].