1. 1 http://WM.tongji.edu.cn Predictive Group Handover Scheme with Sub-Channel Borrowing for IEEE 802.16j- enabled Vehicular Networks Broadband Wireless Communication and Multimedia Laboratory, Tongji University Lianhai Shan shanlianhai@hotmail.com

2. 2 http://WM.tongji.edu.cn Outline Features of Group Handover and Problems Statement Proposed Scheme: PGHO-CB Performance Analysis Simulation Scenario and Result Analysis Conclusion and Future Work

3. 3 http://WM.tongji.edu.cn Mobile RS Application Scenario Relay Station: Enhance the signal strength Extend the coverage

4. 4 http://WM.tongji.edu.cn Group Handover Scenario Broadband Wireless Access using IEEE802.16j for Mobile Multi-hop WiMAX SINR of a neighbor BS is larger than the current serving BS, (the hysteresis margin, threshold), then the handover of group users will happen.

5. 5 http://WM.tongji.edu.cn Problems for Group Users Heavy burden for BS Long system delay in the GHO process Handover dropping probability

6. 6 http://WM.tongji.edu.cn Outline Features of Group Handover Problems Statement Proposed Scheme: PGHO-CB Performance Analysis Simulation Scenario and Result Analysis Conclusion and Future Work

7. 7 http://WM.tongji.edu.cn GHO Flow Chart

8. 8 http://WM.tongji.edu.cn Proposed Scheme Predictive Group Handover (PGHO) Location and moving direction information Channel Borrowing (CB) Borrowing Channels from the existing service in the target BS by decreasing the QoS level. PGHO-CB: Predictive Group Handover with sub-channel borrowing

9. 9 http://WM.tongji.edu.cn Proposed Scheme Mobile direction serving BS ID, average dwelling time, next target BS ID Count On route(ID_1, T100, ID_3)22 On route(ID_1, T60, ID_4)5 On route……… Return route(ID_8, T80, ID_6)20 Return route(ID_8, T120, ID_7)4 Return route…… Movement History Database Large vehicles moving routes is fixed such as light rails, subways.

10. 10 http://WM.tongji.edu.cn Proposed Scheme Erlang-B formula reversely to estimate the number of sub- channel required Result: : CBP of nrtPS in a BS; : CBP of rtPS in a BS; is the number of sub-channels needed for the coming GHO is available sub-channels in the target BS

11. 11 http://WM.tongji.edu.cn Proposed Scheme Sub-Channel Borrowing (CB) for PGHO Detailed CB is within my published papers, will appear in LNCS of Apweb09.

12. 12 http://WM.tongji.edu.cn Outline Features of Group Handover Problems Statement Proposed Scheme Performance Analysis Simulation Scenario and Result Analysis Conclusion and Future Work

13. 13 http://WM.tongji.edu.cn Single Handover Model 2-D Markov state transition diagram

14. 14 http://WM.tongji.edu.cn Single Handover New calls blocking probability (CBP) of rtPS and nrtPS handover blocking probability (HBP) of rtPS and nrtPS rtPS nrtPS rtPS nrtPS

15. 15 http://WM.tongji.edu.cn Proposed Group Handover Markov transition diagram for a Single MS using PGHO scheme Markov transition diagram for a Group MSs using PGHO scheme

16. 16 http://WM.tongji.edu.cn Proposed Group Handover New calls blocking probability (CBP) of rtPS and nrtPS

17. 17 http://WM.tongji.edu.cn Proposed Group Handover handover blocking probability (HBP) of rtPS and nrtPS

18. 18 http://WM.tongji.edu.cn Adaptive HO CAC Delay : represents the handover CAC adaptive factor : represents exponential factor, decided by the different service types : the highest speed : the largest handover CAC delay time : the least handover CAC delay time as

19. 19 http://WM.tongji.edu.cn HO Dropping under Different Velocity : HBP in the handover CAC process : the time of handover CAC process of each time : practical delay of handover CAC process If, handover QoS will reduce If, handover dropping will happen the longest handover CAC delay that can ensure the connection

20. 20 http://WM.tongji.edu.cn Outline Features of Group Handover Problems Statement Proposed Scheme Performance Analysis Simulation Scenario and Result Analysis Conclusion and Future Work

21. 21 http://WM.tongji.edu.cn Simulation Parameter parametersvalue Number of Cells19 Operating Frequency2500MHz DuplexTDD System Channel Bandwidth10MHz BS Height32 meters Mobile Terminal Height1.5 meters BS Antenna Gain15 dBi MS Antenna Gain-1 dBi BS Maximum Power Amplifier Power43 dBm Thermal Noise-174 dBm/Hz Sampling Frequency11.2MHz FFT Size (N FFT )1024 Sub-Carrier Frequency spacing10.94kHz Frame Duration(TTI)5 milliseconds Number of OFDMA Symbols48 Propagation ModelCOST231-Hata

22. 22 http://WM.tongji.edu.cn Simulation Parameter parametersvalue Number of Channels30 Dwelling time0.5 Call completion rate =0.5 new call arrival rates of rtPS new call arrival rates of nrtPS System traffic load channel number of one rtPS (min-max)2-4 channel number of one nrtPS (min-max)1-3 radius of BS coverage 1.28 km

23. 23 http://WM.tongji.edu.cn New calls and HO blocking probability

24. 24 http://WM.tongji.edu.cn Handover dropping probability

25. 25 http://WM.tongji.edu.cn Average handover delay

26. 26 http://WM.tongji.edu.cn Outline Features of Group Handover Problems Statement Proposed Scheme Performance Analysis Simulation Scenario and Result Analysis Conclusion and Future Work

27. 27 http://WM.tongji.edu.cn Conclusion PGHO-CB predict the target BS for mobile RS Target BS prepare the needed resource for HO using the Sub-Channel Borrowing Decrease the HDP significantly of group handover

28. 28 http://WM.tongji.edu.cn Future Work Two-level Channel Reallocation for Group Handover after Sub-channel Borrowing System Performance of GHO

29. 29 http://WM.tongji.edu.cn Thanks Q&A