Kwangjae Lim

Performance analysis for terrestrial radio waveform for control and non-payload communication of unmanned aircraft systems

Necessity for interoperable control and non-payload communication technology and system deployment is increased for safe unmanned aircraft system (UAS) operation as well as extension of UAS applications. For this, C-band frequency was globally allocated only for CNPC in world radio conference 2012 (WRC-12). The technology development and standardization activities for high reliable UAS CNPC operating in the C-band frequency has already been kicked off in US and efficient radio communication technologies are being considered with respect to the size, weight, power and cost (SWaP-C) of UAS. In this paper, we analyze the terrestrial radio waveform standardized in radio technical commission for aeronautics (RTCA) and make some proposals for its performance enhancement.

Network architecture for control and non-payload communication of UAV

For the safe control of Unmanned Aerial Vehicle (UAV), a reliable communication link is very important, so a Control and Non-Payload Communication (CNPC) standard is progressing in Radio Technical Commission for Aeronautics (RTCA) [1][2]. The CNPC standard of RTCA only includes the physical layer specification, so a network architecture and upper layer protocols are required for the CNPC network deployment. In this paper, we propose the LTE based network architecture and the LTE based upper layer protocols. In addition, we propose a security architecture for the CNPC.

Mobile WiMAX Performance Measurements and the selection of path loss model for UGV

Mobile WiMAX is a rapidly growing broadband wireless access technology based on IEEE 802.16e-2005 air-interface standards. It provides high-speed internet service anytime, anywhere, from anyone and any device with seamless mobility and the service is located between mobile phone and wireless LAN. For special activities purpose, we have developed Mobile WiMAX communication systems for UGV (Unmanned Ground Vehicle). This paper present performance results and path loss model for Mobile WiMAX communication system for cell coverage prediction. As little or no published data exists about measurements in LOS (Line of Sight) field trials for Mobile WiMAX, we set up a test-bed and performed cell coverage measurements. We predicted a optimal path loss model through calculating RSSI (Received Signal Strength Indicator). In this paper, the 2-ray ground reflection model was selected an optimal path loss model in this Mobile WiMAX Performance Measurements.

Transmission timing configuraiton for control and non-payload communication of unmanned aerial vehicle

For the safe control of Unmanned Aerial Vehicle (UAV), a reliable communication link is very important, so a Control and Non-Payload Communication (CNPC) standard is progressing in Radio Technical Commission for Aeronautics (RTCA) [1][2]. Currently, CNPC standard only includes the physical layer specification, so the upper layer protocol is required for implementing a CNPC transceiver. In this paper, we assume that the LTE based upper layer protocol is implemented in Digital Signal Processing (DSP) board, and analyze the configuration of timing ticks for reducing transmission delay. The application of half subframe tick can decrease 38.4% of transmission delay compared with the subframe tick.