• Title, Summary, Keyword: IEEE 802.15.4

Search Result 646, Processing Time 0.053 seconds

Multi-channel QoS scheduling algorithm in IEEE 802.15.4e (IEEE 802.15.4e 멀티 채널 QoS 스케줄링 알고리즘)

  • Wu, Hyuk;Kim, Hak-Kyu;Lee, Dong-Jun;Kang, Ho-Yong
    • The Journal of Advanced Navigation Technology
    • /
    • v.15 no.5
    • /
    • pp.764-773
    • /
    • 2011
  • IEEE 802.15.4 is a standard for LWPAN based on TDMA. IEEE 802.15.4 has not been used widely because of restrictions on the QoS, scalability, and reliability. IEEE 802.15.4 utilizes GTS for one-hop QoS transmission. However GTS is not an effective method to satisfy QoS in multi-hop environments. Currently IEEE 802.15.4e, an extended version of IEEE 802.15.4 MAC sub-layer, is being developed to satisfy more diverse performance requirements than IEEE 802.15.4. IEEE 802.15.4e provides muti-hop QoS transmission functionality and uses multiple frequency channels. In this paper, a multi-channel TDMA scheduling scheme is proposed to satisfy end-to-end transmission delay in IEEE 802.15.4e. The performance of the proposed scheme is evaluated using simulation.

Channel Searching Method of IEEE 802.15.4 Nodes for Avoiding WiFi Traffic Interference (WiFi 트래픽 간섭을 피하기 위한 IEEE 802.15.4 노드의 채널탐색방법)

  • Song, Myong Lyol
    • Journal of Internet Computing and Services
    • /
    • v.15 no.2
    • /
    • pp.19-31
    • /
    • 2014
  • In this paper, a parallel backoff delay procedure on multiple IEEE 802.15.4 channels and a channel searching method considering the frequency spectrum of WiFi traffic are studied for IEEE 802.15.4 nodes to avoid the interference from WiFi traffic. In order to search the channels being occupied by WiFi traffic, we analyzed the methods measuring the powers of adjacent channels simultaneously, checking the duration of measured power levels greater than a threshold, and finding the same periodicity of sampled RSSI data as the beacon frame by signal processing. In an wireless channel overlapped with IEEE 802.11 network, the operation of CSMA-CA algorithm for IEEE 802.15.4 nodes is explained. A method to execute a parallel backoff procedure on multiples IEEE 802.15.4 channels by an IEEE 802.15.4 device is proposed with the description of its algorithm. When we analyze the data measured by the experimental system implemented with the proposed method, it is observed that medium access delay times increase at the same time in the associated IEEE 802.15.4 channels that are adjacent each other during the generation of WiFi traffic. A channel evaluation function to decide the interference from other traffic on an IEEE 802.15.4 channel is defined. A channel searching method considering the channel evaluations on the adjacent channels together is proposed in order to search the IEEE 802.15.4 channels interfered by WiFi, and the experimental results show that it correctly finds the channels interfered by WiFi traffic.

Improving BER Performance of IEEE 802.15.4 with Alamouti Scheme in MIMO System (MIMO 시스템에서 ALAMOUTI 기법과 IEEE 802.15.4의 BER 성능 개선)

  • Halim, Eddy Hartono;Shin, Soo-Yong
    • Journal of Internet Computing and Services
    • /
    • v.14 no.1
    • /
    • pp.1-7
    • /
    • 2013
  • This paper proposes a technique for applying space-time block coding (STBC) - Alamouti scheme on Multiple Inputs Multiple Output (MIMO) system based on IEEE 802.15.4 standard. It is applied to IEEE 802.15.4 standard in $2{\times}1$ MISO and $2{\times}2$ MIMO systems. Simulation is performed using Matlab and the results are compared with conventional IEEE 802.15.4 approaches, Single Input Single Output (SISO) system and switching diversity $1{\times}2$ Single Input Multiple Output (SIMO) system. The simulations show that applied Alamouti scheme gave better Bit Error Rate (BER) performance compared to combined IEEE 802.15.4 with switching diversity and SISO system.

Coexistence Mechanism between IEEE 802.15.4 and IEEE 802.11 : ACROS (IEEE 802.15.4 와 IEEE 802.11의 공존 방법 : ACROS)

  • Shin, S.Y.;Lee, J.W.;Kwon, W.H.;Shin, Y.H.;Kim, Y.H.;Kim, J.J.;Kim, Yu-Shin
    • 한국정보통신설비학회:학술대회논문집
    • /
    • /
    • pp.74-84
    • /
    • 2005
  • In this paper, a new coexistence mechanism between IEEE 802.15.4 and IEEE 802.11, ACROS (Active Channel Reservation for coexistence), is proposed. The key idea of ACROS is to reserve the channel for IEEE 802.15.4 transmission. During the reservation, IEEE 802.11 transmissions cannot be occurred. Request-to-send/clear-to-send mechanism of IEEE 802.11 is used to reserve channel. The proposed ACROS mechanism is implemented into PC based prototype. By the experiments, the $e{\pm}ciency$ of ACROS is proved.

  • PDF

Frame Transmission and Channel Changing Methods of IEEE 802.15.4 Nodes in WiFi Traffic Interference Environment (WiFi 트래픽의 간섭환경에서 IEEE 802.15.4 노드의 프레임 전송 및 채널변경 방법)

  • Song, Myong Lyol
    • Journal of Internet Computing and Services
    • /
    • v.15 no.1
    • /
    • pp.179-191
    • /
    • 2014
  • In this paper, a frame transmission method to make IEEE 802.15.4 nodes run at a new channel and its characteristics are studied when they experience difficulties in transmission of frames due to WiFi traffic. The researches on evaluating the interference from WiFi traffic, searching for a new channel with little interference or not, and changing the operating channel are analyzed. In an wireless channel overlapped with IEEE 802.11 network, the transmission delay of IEEE 802.15.4 frames, the collision of frames in sending IEEE 802.15.4 frames without applying CSMA-CA algorithm, and the operation of IEEE 802.11 nodes are explained. A transmission method of frames including frame-formated code blocks in order to use the rest part of collided IEEE 802.15.4 frame is proposed. In the experiments of the proposed method, it is observed that frame-formated code blocks are synchronized and received by receivers in case of collision, and then the collided positions in IEEE 802.15.4 frame and the characteristics of frame reception rate are analyzed. The experimental results show that the performance of the proposed method is improved in comparison to an existing method when we measure the time taken to send a channel change command and get the response in order to avoid the interference from WiFi traffic.

Implementation of IEEE 802.15.4 Channel Analyzer for Evaluating WiFi Interference (WiFi의 간섭을 평가하기 위한 IEEE 802.15.4 채널분석기의 구현)

  • Song, Myong-Lyol;Jin, Hyun-Joon
    • The Transactions of the Korean Institute of Electrical Engineers P
    • /
    • v.63 no.2
    • /
    • pp.81-88
    • /
    • 2014
  • In this paper, an implementation of concurrent backoff delay process on a single chip with IEEE 802.15.4 hardware and 8051 processor core that can be used for analyzing the interference on IEEE 802.15.4 channels due to WiFi traffics is studied. The backoff delay process of IEEE 802.15.4 CSMA-CA algorithm is explained. The characteristics of random number generator, timer, and CCA register included in the single chip are described with their control procedure in order to implement the process. A concurrent backoff delay process to evaluate multiple IEEE 802.15.4 channels is proposed, and a method to service the associated tasks at sequentially ordered backoff delay events occurring on the channels is explained. For the implementation of the concurrent backoff delay process on a single chip IEEE 802.15.4 hardware, the elements for the single channel backoff delay process and their control procedure are used to be extended to multiple channels with little modification. The medium access delay on each channel, which is available after execution of the concurrent backoff delay process, is displayed on the LCD of an IEEE 802.15.4 channel analyzer. The experimental results show that we can easily identify the interference on IEEE 802.15.4 channels caused by WiFi traffics in comparison with the way displaying measured channel powers.

Bridge between IEEE 802.15.4 and IEC 61850 using Raspberry Pi (라즈베리파이를 이용한 IEEE 802.15.4와 IEC 61850 간의 브리지)

  • Hwang, Sung-Ho
    • The Journal of The Institute of Internet, Broadcasting and Communication
    • /
    • v.17 no.5
    • /
    • pp.181-186
    • /
    • 2017
  • IEC 61850 is a standard for power utility automation. Using IEC 61850 that uses ethernet may consume more costs for the automation than its value in small distribution substations. Thus, less expense and installation cost are required for the automation of small distribution substations. This study used inexpensive and easy-to-install IEEE 802.15.4 and implemented a bridge between IEC 61850 and IEEE 802.15.4, using Raspberry Pi to connect the existing IEC 61850. Using IEEE 1588, IEC 61850 traffic performances were evaluated, such as SV, GOOSE and MMS. Analyzing IEC 61850 requirements and performance evaluation results, the scope of application of IEEE 802.15.4 was decided.

Mitigating Hidden Nodes Collision and Performance Enhancement in IEEE 802.15.4 Wireless Sensor Networks (IEEE 802.15.4 기반의 무선 센서네트워크에서 숨은노드 충돌 방지와 성능향상 기법)

  • Ahn, Kwang-Hoon;Kim, Taejoon
    • KIPS Transactions on Computer and Communication Systems
    • /
    • v.4 no.7
    • /
    • pp.235-238
    • /
    • 2015
  • IEEE 802.15.4 is the well-established standard enabling wireless connectivities among wireless sensor nodes. However, the wireless sensor networks based on IEEE 802.15.4 are inherently vulnerable to hidden nodes collision because the wireless sensor nodes have very limited communication range and battery life time. In this paper, we propose the advanced method of mitigating hidden nodes collision in IEEE 802.15.4 base wireless sensor networks by clustering sensor nodes according to channel quality information. Moreover, we deal with the problem of resource allocation for each cluster.

Performance Evaluation on the Power Consumption of IEEE802.15.4e TSCH (IEEE802.15.4e TSCH의 소비전력에 대한 성능평가)

  • Kim, Dongwon;Youn, Mi-Hee
    • The Journal of The Institute of Internet, Broadcasting and Communication
    • /
    • v.18 no.1
    • /
    • pp.37-41
    • /
    • 2018
  • In this paper, we evaluate the power consumption of IEEE802.15.4e TSCH which uses the specific link scheduling scheme proposed in reference[1]. And we also compares it with the power consumption of conventional single channel IEEE802.15.4. The power consumption of IEEE802.15.4e TSCH is smaller than the conventional one under the any conditions of traffic. The reasons can be explained as the followings. Firstly, TSCH does not have backoff time because of using the collision free link scheduling. Secondly, there is the timing difference of MAC offset parameter between TSCH and conventional IEEE802.15.4 Lastly, the devices in TSCH mode sleep during the time slots which are not assigned to itself.

Implementation of IEEE 802.15.4 Protocol Stack on the Texas Instrument CC2530 (텍사스 인스트루먼트의 CC2530 상에 IEEE 802.15.4 프로토콜 스택 구현)

  • Kim, Byung-Soon
    • Journal of Digital Contents Society
    • /
    • v.13 no.3
    • /
    • pp.353-358
    • /
    • 2012
  • Wireless sensor networks consist of resource constraint devices which typically send data measured by sensors attached to the end devices towards a coordinator. The most often used medium access control protocol used in wireless sensor networks is the standard IEEE 802.15.4, where it is wireless standard introduced for low power, low cost wireless communication with moderate data rates. In this paper, we present implementation of both the IEEE 802.15.4 protocol stack and UART interface on the TI CC2530. We show that data via UART of our implemented IEEE 802.15.4 board are transmitted correctly in terms of captured frames.