1. Submission doc.: IEEE 802.15-15-0242-007a Kookmin University Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Kookmin University Response to 15.7r1 CFA: Asynchronous OCC in Vehicular environment] Date Submitted: [May, 2015] Source: [Trang Nguyen, Md. Shareef Ifthekhar, Nam Tuan Le, Chang Hyun Hong, Mohammad Arif Hossain, Nirzhar Saha, and Yeong Min Jang,] [Kookmin University] Address [Kookmin University, Seoul, Korea] Voice:[82-2-910-5068], FAX: [82-2-910-5068], E-Mail:[yjang@kookmin.ac.kr] Re: [] Abstract: Purpose:Call for Application Response Notice:This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15. Yeong Min Jang, Kookmin University Doc.: IEEE 802.15-15-0389-00-007a May 2015

2. Submission doc.: IEEE 802.15-15-0242-007a Kookmin University May 2015 Slide 2 Kookmin University Response to 15.7r1 CFA: Asynchronous OCC in Vehicular environment Yeong Min Jang yjang@kookmin.ac.kr

3. Submission doc.: IEEE 802.15-15-0389-00-007a Kookmin University Slide 3 May 2015 Contents  Scenario asynchronous OCC in vehicular environment  Challenging issues  Other considerations  Conclusion Reference: Trang Nguyen, Nam Tuan Le, and Yeong Min Jang, “Asynchronous Scheme for Optical Camera Communication-Based Infrastructure-to-Vehicle Communication,” International Journal of Distributed Sensor Networks, Article ID 908139, in press. http://www.hindawi.com/journals/ijdsn/aa/908139/

4. Submission doc.: IEEE 802.15-15-0389-00-007a Kookmin University Slide 4 May 2015 Scenario of Asynchronous I2V Unidirectional OCC Asynchronous OCC is promising in vehicular environment Vehicles will be installed with full cameras as indispensable safety sensors

5. Submission doc.: IEEE 802.15-15-0389-00-007a Kookmin University Slide 5 May 2015 Scenario of asynchronous OCC in vehicular environment Digital Signage I2V and Relaying V2V Asynchronous OCC is promising in vehicular environment

6. Submission doc.: IEEE 802.15-15-0389-00-007a Kookmin University Slide 6 May 2015 Challenging Issues Camera operation: Exposure time and bad-sampling The moment of capture and the appearance of good/poor quality image frames. Occurrence of poor image frames. Exposure time causes bad-samplings

7. Submission doc.: IEEE 802.15-15-0389-00-007a Kookmin University Slide 7 May 2015 Challenging Issues Camera operation: Frame rate variation Day time Night time Experiment of variation in camera frame rate by measuring inter-frame interval Model of variation in camera frame rate Variation in camera frame rate and switch of frame rate between daytime and nighttime

8. Submission doc.: IEEE 802.15-15-0389-00-007a Kookmin University Slide 8 May 2015 802.15.7r1 (Various) Challenging Issue  Rate adaption with distance At short-distance full-multiplexing mode At far-distance full-diversity mode

9. Submission doc.: IEEE 802.15-15-0389-00-007a Kookmin University Slide 9 May 2015 Other considerations The estimated BER varies based on the variation in the frame rate of the high- speed camera (which is around 1,000 fps).  Error correction scheme is needed for correcting error caused by bad-sampling Bad-sampling and the need of error correction

10. Submission doc.: IEEE 802.15-15-0389-00-007a Kookmin University Slide 10 May 2015 Other considerations Transmitted red light and received signals in red/green/blue channels.  Presence of interference between colors-channels due to response of Bayer filter in front of image sensor

11. Submission doc.: IEEE 802.15-15-0389-00-007a Kookmin University Slide 11 May 2015 802.15.7r1 (Various) Asynchronous definition By using normal types of camera, it is practically recorded that the camera frame rate is unstable (the variation of camera frame rate). This causes the mismatching frame rates between transmitter and receiver.  The purpose of asynchronous communication scheme is to help camera receiver can decode data under presence of heterogeneous frame rates for unidirectional communication.

12. Submission doc.: IEEE 802.15-15-0389-00-007a Kookmin University Slide 12 May 2015 802.15.7r1 (Various) Asynchronous definition  Like RS 232 it has start bit and stop bit and also transmitter and receiver both know number of data bits.  However RS232 sampling rate is constant but Asynchronous scheme will allow unstable sampling rate ( unstable camera frame rates with in certain limit)

13. Submission doc.: IEEE 802.15-15-0389-00-007a Kookmin University Slide 13 May 2015 802.15.7r1 (Various) Conclusion  Use case of OCC in I2V/V2V for safety reasons including cooperative driving and collision avoidance  Need PHY support asynchronous communication for unidirectional system (4.1.5 Transfer Mode)  Need of error correction due to bad-sampling (4.1.14 Error detection)  Need PHY supports high-speed camera (4.1.3 receiver -----> Specify camera frame rates for A4 application)  Need PHY supports variable link rate (rate adaption) (4.1.8 Communication range i.e. specify multiplexing and diversity modes with distance)