• The Journal of the Korea Contents Association
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• v.16 no.11
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• pp.83-90
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• 2016

In this paper, we performed the analysis of transmission performance for Collision Free Period(CFP) supported by the low-power communication technology, IEEE 802.15.4 MAC (Media Access Control). For the analysis, periodic traffic, original service target of CFP, is considered and, according to the Quality of Service required, packet arrival pattern to MAC layer is categorized as batch and non-batch, and analysis on throughput, delay, and energy is performed for those patterns. On the basis of the obtained analysis, performance comparison with Collision Avoidance Period(CAP) is carried out for the health care applications that generate periodic traffic such as Pedometer, ECG, EMG. The evaluation confirms that CFP is more energy efficient for healthcare applications that generate periodic and time-critical traffic and moreover for the application with high bandwidth requirement CFP achieves up to 46% energy savings compared to CAP.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.4
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• pp.436-440
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• 2008

In IEEE 802.15.4 beacon-enabled mode, performance decreases as the number of devices competing in the contention access period(CAP) increases. In this letter, we propose partitioned contention access mechanism(PCAM) to compensate performance degradation. In PCAM, the PAN coordinator divides CAP into two sub-periods and activity of devices is delimited in their assigned sub-periods. Since PCAM reduces the number of devices which compete at the same time by half, collision probability between transmitted frames can be reduced. In addition, devices can save their power consumption because PCAM shorten the duration that devices stay in active state into half. We perform simulations to compare the performance of PCAM with that of the IEEE 802.15.4 standard. From the result, PCAM yields better performance than IEEE 802.15.4 standard.

• Journal of Korea Society of Industrial Information Systems
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• v.18 no.6
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• pp.17-24
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• 2013

The localization accuracy in wireless sensor networks using ranging-based localization algorithms is greatly influenced by the ranging accuracy. Software implementation of HAL(Hardware Abstraction Layer) and MAC(Medium Access Layer) should seamlessly deliver the raw performance of ranging-based localization provided by hardware capability fully to the applications without degrading the raw performance. This paper presents the design and implementation of the software stack for IEEE 802.15.4a which supports normal ranging mode of the Nanotron's NA5TR1 RF chip. The experiment results shows that average ranging error rate with our implementation is 24.5% for the normal mode of the SDS-TWR ranging scheme.

• 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.

• Journal of Korea Multimedia Society
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• v.14 no.11
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• pp.1420-1430
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• 2011

This paper proposes a new method to optimize energy consumption in a wireless modem by setting up a transmission power value according to the distance between nodes and circumstance in the MAC layer of IEEE 802.15.4. The proposed method can dynamically find an optimal transmission power range using the binary search scheme and minimize overhead caused by multiple message transmissions when determining the optimal transmission power. The determined transmission power is used for transmitting data packets and can be modified dynamically depending on the changes in a network environment when exchanging data packets and acknowledgement signals. The results of the simulations show 30% reduction in energy consumption while 2.5 times increase in data transmission rate per unit of energy comparing with IEEE 802.15.4 standard.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.274-276
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• 2005

무선 센서 네트워크는 수많은 노드들 간의 상호작용에 의해 서로 통신을 한다. 이러한 센서 네트워크에 대한 프로토클 구현은 정확한 동작을 확인하기 위해 많은 노드들을 배치하여 실제 동작을 확인하며 개발을 해야 하는 번거로움을 갖고 있다. 본 논문에서는 무선 센서 네트워크에 적합한 프로토콜인 IEEE 802.15.4의 PHY 계층에 대한 시뮬레이터를 구현하여 여러 노드들이 있는 상황을 시abf레이션 할 수 있는 환경을 갖춰서 상위 MAC 프로토콜의 동작을 검증할 수 있는 기반 환경을 구현 하였다.

• Journal of information and communication convergence engineering
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• v.5 no.3
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• pp.200-204
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• 2007

The release of IEEE 802.15.4 PHY-MAC standard represents a milestone in developing of commercial wireless sensor network pursuing low power and low cost. In this paper, IEEE 802.15.4 Medium Access Control (MAC) protocol was analysed at the point of power consumption. This analysis measured the amount of the rest of power after transmitting data with beacon enabled mode and the power consumption of each node in the time period. ns-2 simulation is used to verify the analysis.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.756-759
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• 2011

산업장 기반 모니터링 시스템에 무선 네트워크 기술의 도입은 시스템 도입 및 유지보수에 있어 반드시 필요하다. 무선 네트워크 기반의 산업장 모니터링을 위해 현재 USN 네트워크에서 광범위하게 사용되고 있는 IEEE 802.15.4 하드웨어 및 MAC 을 이용하여 Freequency Hopping을 수행하는 Superframe 기반의 TDMA 기술을 구현하였다.

• The KIPS Transactions:PartC
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• v.16C no.3
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• pp.407-416
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• 2009

Recently, various application services in wireless sensor networks are more considered than before, and thus reliable and secure communication of sensor network is turning out as one of essential issues. This paper studies such communication in IEEE 802.15.4 based sensor network. We present IMHRS (IEEE 802.15.4 MAC-based Hybrid hop-by-hop Reliability Scheme) employing EHHR (Enhanced Hop-by-Hop Reliability), which uses Hop-cache and Hop-ack and ALC (Adaptive Link Control), which considers link status and packet type. Also, by selecting security suite depending on network and application type, energy efficiency is considered based on HAS (Hybrid Adaptive Security) Framework. The presented schemes are evaluated by simulations and experiments. Besides, the prototype system is developed and tested to show the potential efficiency.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.3
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• pp.293-299
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• 2016

Recently, as IoT (Internet of Things) becomes more important, low cost implementation of sensor nodes also becomes critical issues for two well-known standards, IEEE 802.15.4 and IEEE 802.15.6 which stands for WPAN (Wireless Personal Area Network) and WBAN (Wireless Body Area Network), respectively. This paper presents the area-optimized AES-CCM (Advanced Encryption Standard - Counter with CBC-MAC) hardware security engine which can support both IEEE 802.15.4 and IEEE 802.15.6 standards. First, for the low cost design, we propose the 8-bit AES encryption core with the S-box that consists of fully combinational logic based on composite field arithmetic. We also exploit the toggle method to reduce the complexity of design further by reusing the AES core for performing two operation mode of AES-CCM. The implementation results show that the total gate count of proposed AES-CCM security engine can be reduced by up to 42.5% compared to the conventional design.