• Title/Summary/Keyword: wireless device communication

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Computational Complexity Comparison of TPMS Beamformers for Interference Suppression (간섭제거를 위한 TPMS 빔형성기들의 복잡도 비교)

  • Kim, Seong-Min;Hwang, Suk-Seung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.7 no.6
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    • pp.1327-1335
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    • 2012
  • TPMS (Tire Pressure Monitoring System) is a safety assistant system to prevent the serious accident due to the damaged tire by the abnormal tire pressure. It is designed to transmit the measured data for pressure and temperature of tires from the sensor unit installed in each tire to signal processing unit installed in a vehicle. Based on the received information, a driver monitors the condition of tires using a display device, to maintain the optimum travelling condition. Since TPMS should employ the wireless communication technique, it may suffer from various interferences from external electrical or electronics devices. In order to suppress them, the beamforming techniques such as switching, minimum-variance distortionless-response (MVDR), and generalized sidelobe canceler (GSC) have been considered for TPMS. In this paper, we calculate computational complexities of three beamformers and suggest mathematical basis to compare their performance of the complexity.

Performance Analysis of Policy-based QoS Algorithm in the IMS (IMS에서 정책기반 QoS 알고리즘의 성능 분석)

  • Han, Seok-Jun;Shon, Hyung-Doh;Kang, Seung-Chan
    • Journal of IKEEE
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    • v.19 no.2
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    • pp.133-141
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    • 2015
  • The IMS is an architectural control framework for delivering IP multimedia services such as voice, video, audio and data, the IMS supports not only the mobile communication system but also the existing wired and wireless network based on IP. The network that is integrated by the IMS needs policy-based network management protocol for managing the limited network resources to provide efficient multimedia service. The IMS use additional device called PDF for efficient resource management, but the PDF only uses diameter which is one of the network management protocol such as SNMP and COPS. Many devices use various protocol to manage the limited network resources. There is an algorithm using a variety of protocols such as Diameter, COPS and SNMP to handle the resources management efficiently. We also analyze the performance using the proposed algorithm in the implemented IMS environment.

Utilization and Optimized Implementation of Format Preserving Encryption Algorithm for IoT and BLE Communications (IoT와 BLE 통신상의 형태보존암호 활용 및 최적화 구현 기법)

  • Lim, Ji-hwan;Kwon, Hyuk-dong;Woo, Jae-min;An, Kyu-hwang;Kim, Do-young;Seo, Hwa-jeong
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.28 no.6
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    • pp.1371-1378
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    • 2018
  • Bluetooth is the key technology in the wireless connection of many Internet of Things (IoT) devices, especially focused on smartphones today. In addition, Bluetooth communication between the IoT device and the user is mainly performed via Bluetooth Low Energy (BLE), but as the Bluetooth technology gradually develops, the security vulnerability of the existing BLE is more prominent. Research on Bluetooth accessibility has been conducted steadily so far, but there is lack of research for data protection in Bluetooth communication. Therefore, in this paper, when sending and receiving data in BLE communication between IoT and users, we propose effective methods for communicating with each other through the Format Preserving Encryption Algorithm (FEA), not the plain text, and measures performance of FEA which is optimized in Arduino and PC.

The Individual Discrimination Location Tracking Technology for Multimodal Interaction at the Exhibition (전시 공간에서 다중 인터랙션을 위한 개인식별 위치 측위 기술 연구)

  • Jung, Hyun-Chul;Kim, Nam-Jin;Choi, Lee-Kwon
    • Journal of Intelligence and Information Systems
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    • v.18 no.2
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    • pp.19-28
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    • 2012
  • After the internet era, we are moving to the ubiquitous society. Nowadays the people are interested in the multimodal interaction technology, which enables audience to naturally interact with the computing environment at the exhibitions such as gallery, museum, and park. Also, there are other attempts to provide additional service based on the location information of the audience, or to improve and deploy interaction between subjects and audience by analyzing the using pattern of the people. In order to provide multimodal interaction service to the audience at the exhibition, it is important to distinguish the individuals and trace their location and route. For the location tracking on the outside, GPS is widely used nowadays. GPS is able to get the real time location of the subjects moving fast, so this is one of the important technologies in the field requiring location tracking service. However, as GPS uses the location tracking method using satellites, the service cannot be used on the inside, because it cannot catch the satellite signal. For this reason, the studies about inside location tracking are going on using very short range communication service such as ZigBee, UWB, RFID, as well as using mobile communication network and wireless lan service. However these technologies have shortcomings in that the audience needs to use additional sensor device and it becomes difficult and expensive as the density of the target area gets higher. In addition, the usual exhibition environment has many obstacles for the network, which makes the performance of the system to fall. Above all these things, the biggest problem is that the interaction method using the devices based on the old technologies cannot provide natural service to the users. Plus the system uses sensor recognition method, so multiple users should equip the devices. Therefore, there is the limitation in the number of the users that can use the system simultaneously. In order to make up for these shortcomings, in this study we suggest a technology that gets the exact location information of the users through the location mapping technology using Wi-Fi and 3d camera of the smartphones. We applied the signal amplitude of access point using wireless lan, to develop inside location tracking system with lower price. AP is cheaper than other devices used in other tracking techniques, and by installing the software to the user's mobile device it can be directly used as the tracking system device. We used the Microsoft Kinect sensor for the 3D Camera. Kinect is equippedwith the function discriminating the depth and human information inside the shooting area. Therefore it is appropriate to extract user's body, vector, and acceleration information with low price. We confirm the location of the audience using the cell ID obtained from the Wi-Fi signal. By using smartphones as the basic device for the location service, we solve the problems of additional tagging device and provide environment that multiple users can get the interaction service simultaneously. 3d cameras located at each cell areas get the exact location and status information of the users. The 3d cameras are connected to the Camera Client, calculate the mapping information aligned to each cells, get the exact information of the users, and get the status and pattern information of the audience. The location mapping technique of Camera Client decreases the error rate that occurs on the inside location service, increases accuracy of individual discrimination in the area through the individual discrimination based on body information, and establishes the foundation of the multimodal interaction technology at the exhibition. Calculated data and information enables the users to get the appropriate interaction service through the main server.

Digital Data Communication System for Mobile Network System Using CC1020 Chip (CC1020 Chip을 사용한 모바일 네트워크를 위한 디지털 데이터 통신 시스템)

  • Lim, Hyun-Jin;So, Heung-Kuk
    • Journal of the Institute of Convergence Signal Processing
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    • v.8 no.1
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    • pp.58-62
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    • 2007
  • Digital communication is important for reliability and mobilization of the multi-channel communication systems. Transmitting and receiving data for the mobilization should be possible in anywhere and in anytime. And this system must be designed light weight small size and low power. One are essential technology for implementing the mobile wireless communication system on the age of ubiquotos. Requirements in constructing such communication field are followings. At first data transmitting and receiving should be carried out by a simple command. Second, the device should be designed as hand-hold type and low power consumption. Third, data communication should be reliable. As one of examples, car to car system which is popular in the market is introduced here, All traffic information in highway is transmitted from one car to another by using this system which can prevent possible traffic accident. This paper shows the design of a digital data communication system with CC1020 chip. This CC1020 makes easy frequency selection and easy switch from the transmit mode to the receive mode by simple setting of a memory register in the chip. The transmit power of this system is designed 10dBm and its communication range is about 100m. The power supplied this system is 3V considered as low power. The sleep mode can be easily entered during transmit mode or receive mode. We shows the program algorithm of CC1020 and interface circuit between MCU and CC1020. We shows the Photo of the CC1020 Module and Atmega128 Module.. We analysed the receiver rate with this system.

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Wireless Data Transmission Algorithm Using Cyclic Redundancy Check and High Frequency of Audible Range (가청 주파수 영역의 고주파와 순환 중복 검사를 이용한 무선 데이터 전송 알고리즘)

  • Chung, Myoungbeom
    • KIPS Transactions on Computer and Communication Systems
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    • v.4 no.9
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    • pp.321-326
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    • 2015
  • In this paper, we proposed an algorithm which could transmit reliable data between smart devices by using inaudible high frequency of audible frequency range and cyclic redundancy check method. The proposed method uses 18 kHz~22 kHz as high frequency which inner speaker of smart device can make a sound in audible frequency range (20 Hz~22 kHz). To increase transmission quantity of data, we send mixed various frequencies at high frequency range 1 (18.0 kHz~21.2 kHz). At the same time, to increase accuracy of transmission data, we send some mixed frequencies at high frequency range 2 (21.2 kHz~22.0 kHz) as checksum. We did experiments about data transmission between smart devices by using the proposed method to confirm data transmission speed and accuracy of the proposed method. From the experiments, we showed that the proposed method could transmit 32 bits data in 235 ms, the transmission success rate was 99.47%, and error detection by using cyclic redundancy check was 0.53%. Therefore, the proposed method will be a useful for wireless transmission technology between smart devices.

Techniques study of IMS/SIP based Lawful Interception in 3G networks (3G 네트워크에서의 IMS/SIP 기반 합법적 감청 기법)

  • Lee, Myoung-rak;Pyo, Sang-Ho;In, Hoh Peter
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.25 no.6
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    • pp.1411-1420
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    • 2015
  • Lawful interception(LI) standard of telephone networks has technical limitations to lawfully intercept IMS/SIP-based mobile communication network subscriber who using Android and iPhone device. In addition, the technical standards related to legal interception of the IMS/SIP of the wireless network is insufficient compared to the systematic study of the development of a wireless network infrastructure. The architecture proposed in the standard of ETSI(European Telecommunications Standards Institute) for the seamless LI is insufficient to overcome the limitations of traditional voice-centric LI techniques. This paper proposes an IMS/SIP-based architecture to perform LI under 3G networks that focuses on mobility-supported environments with merging cellular networks and the Internet. We implemented the simulation to verify the efficiency of the proposed architecture, and the experimental results show that our method achieves higher lawful interception rate than that of existing interception methods.

Load Distribution Method based on Transcoding Time Estimation on Distributed Transcoding Environments (분산 트랜스코딩 환경에서 트랜스코딩 시간 예측 기반 부하 분산 기법)

  • Kim, Jong-Woo;Seo, Dong-Mahn;Jung, In-Bum
    • Journal of KIISE:Computer Systems and Theory
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    • v.37 no.4
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    • pp.195-204
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    • 2010
  • Due to improved wireless communication technologies, it is possible to provide multimedia streaming service for mobile device clients like PDAs and cellphones. Wireless networks are serviced on low bandwidth channels and mobile devices work on limited hardware specifications. In these conditions, transcoding technologies are needed to adapt the media for streaming services to given mobile environments. To transcode from the source media to the target media for corresponding grades, transcoding servers perform transcoding jobs as exhausting their resources. Since various transcoding loads occur according to the target transconding grades, an effective transcoding load balancing policy is required among transcoding servers. In addition to transcoding process, servers should maintain QoS streams for mobile clients for total serviced times. It requires real-time requirements to support QoS for various mobile clients. In this paper, a new transcoding load distribution method is proposed. The proposed method can be driven for fair load balance between distributed transcoding servers. Based on estimated transcoding time, movie information and target transcoding bit-rate, it provides fair transcoding load distribution and also performs admission control to support QoS streams for mobile clients.

Wired/Wireless Gateway System Supporting LAN-to-LAN VPN with Multi-Queuing Realtime Traffic Shaping (다중큐잉 실시간 트래픽쉐이핑을 적용한 네트워크간 VPN 지원 유무선공유기 시스템)

  • Yang, Seung Eui;Goh, Byung Oh;Choi, Jong-Kun;Jung, Hoe-kyung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.5
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    • pp.1097-1103
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    • 2015
  • In order to build network infrastructure to implement the aforementioned advantages enabling smart device users to work anywhere, professional support and expensive VPN devices are required. This is a barrier to supplying VPN devices to small and medium-sized institutes. To address this issue, this study aims to implement OpenVPN, OpenSSH and iproute based on the OpenWRT platform which is an embedded OS for open networks in affordable open wired/wireless gateway H/W platforms to support the inter-network VPN. In addition, the network environment can be maintained optimal by applying a "multi-queuing real-time traffic shaping technology" to VPN tunnels, although channel quality changes.

A Deterministic Access Protocol in WiMedia Wireless Personal Area Networks (WiMedia 초고속 근거리 무선 통신에서의 결정적 접근 프로토콜)

  • Park, Hyun-Hee;Pack, Sang-Heon;Kim, Yong-Sun;Kang, Chul-Hee
    • Journal of IKEEE
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    • v.13 no.3
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    • pp.7-17
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    • 2009
  • WiMedia UWB technology is a fully distributed data communication technology developed for the application demanding a high data transmission rate in the wireless PAN area. In general, devices can send data either by reserving time slots or by using prioritized CSMA/CA. If the PCA protocol of prioritized CSMA/CA is used, they are suffered congestion as the number of devices increases. In this paper, we propose a Deterministic Access Protocol(DAP) in WiMedia WPANs. A DAP is a method to transmit data in the non-reserved DRP period without competition as each device informs the beacon order information in the beacon period and the queue information. In addition, the problem that the devices with a lower beacon slot number have more transmission opportunities is addressed by introducing the reference point. Simulation results are given to demonstrate that a DAP can improve the throughput and reduce the packet loss rate.

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