VANET Link Characteristics and Analysis in Urban and Suburban Scenarios

1. VANET Link Characteristics and Analysis in Urban and Suburban Scenarios Yang Yang lun Xu Da Cheng Li-hua Wu Peng-ju Tan Lin-tao Yang Department of Electronic Information, Wuhan University, Hubei, Wuhan 430079, China 報告： 史晉銘組員： 69821009 史晉銘 69821024 江宗儫 69821044 葉人誠

2. Outline • Introduction • Background and Related Work • Experimental Setup and Details • Experimental Results and Analysis • Conclusion

3. Introduction • The performance of VANET is the most significant issue • Our application aim to provide continuous update about traffic conditions, which can assist the quality prediction of wireless link and the protocol design of VANET

4. Experimental Setup and Details

5. Experimental Setup and Details • RSSI(Received Signal Strength Indicator); PLR(Packet Loss Rate) • IBM laptop computer • Wi-Fi (Antenna higher than 3.2 m ) • Broadcast data rate : 1Mb/s • Leading vehicle(TX) Receiver vehicle(RX)

7. Experimental Results and Analysis • Effect of Environmental Diversity to Wireless Link • Effect of RSSI to VANET Wireless Link • Predicting the VANET Wireless Link by PLBL

8. Effect of Environmental Diversity to Wireless Link • the averages of the PLRs are different in various distance scales • In distance range in 30m, the performance of the two scenarios almost the same (the variation is less than 2%) • beyond 30m, the averages of PLRs of the urban scenario are superior to that of the suburban scenario • in 70m area, the difference of the two scenarios is between 10-15%

9. Effect of RSSI to VANET Wireless Link • over 70m, the average of PLRs tends to be lower; however, the RSSI is still worse • Comparing 50-60m 70-80m, the reductions of the average of PLR is about 15, even though the RSSI of them is very • The same results arerevealed in different distances

10. Predicting the VANET Wireless Link by PLBL • The packet sequence is represented as a binary sequence {Xk}. If the kth packet is lost, Xk =1; while the kth packet is receives, Xk=0 • A burst is defined as a string of consecutive ones between two zero and PLBL is defined to be the number of ones

11. Classified as two condition as follow: • Suppose {0110} : The packet lose are consecutive • Suppose {0101} : The packet lose of signal packet error is random • Let P be defined as the packet loss rate • s : {0110,01110,011110,….}; the possibility of the • Constant Packet Loss Rate • t : {010}; the possibility of the Random Packet Loss Rate

12. Predicting the VANET Wireless Link by PLBL

13. Conclusion • Environment affects the quality of the wireless link in VANET greatly • At the communication distance range, in most extend, the PLR is related to the distance variation • RSSI is not coherent with PLR, which is not helpful in predicting the quality of the VANET wireless link • In certain aspects, the sum of possibilities of PLBL is another way to predict the 802.11 wireless channel quality

14. Q&A