Diese Präsentation wurde erfolgreich gemeldet.
Die SlideShare-Präsentation wird heruntergeladen. ×

Game based TDMA MAC protocol for vehicular network

Anzeige
Anzeige
Anzeige
Anzeige
Anzeige
Anzeige
Anzeige
Anzeige
Anzeige
Anzeige
Anzeige
Anzeige

Hier ansehen

1 von 25 Anzeige
Anzeige

Weitere Verwandte Inhalte

Diashows für Sie (20)

Ähnlich wie Game based TDMA MAC protocol for vehicular network (20)

Anzeige

Aktuellste (20)

Game based TDMA MAC protocol for vehicular network

  1. 1. Game-based TDMA MAC Protocol for Vehicular Network
  2. 2. Flow of Talk  Introduction  System Model  Game-Based Slot Reservation Mechanism  Performance Analysis  Simulation Result and Analysis  Conclusion  References
  3. 3. Introduction  Challenges in VANET ◦ Topology is highly dynamic due to the moving vehicles. ◦ Frequent path breaks and high density of nodes. ◦ Interference because of movement of intermediate nodes or end nodes. ◦ Routing protocol should aware of frequent topology changes. ◦ Frequent disconnection of nodes create problem in designing protocol for traffic information exchange. ◦ Heterogeneous vehicle management ◦ Uses both push and pull models for data exchange. The vehicular ad hoc network (VANET) is a special network that applies the mobile ad hoc network (MANET) to traffic scenarios.
  4. 4. Contd…  Some previously used protocols for VANET ◦ IEEE 802.11p, HER-MAC, CFR-MAC, CAH-MAC .  Disadvantages of above protocols ◦ Hidden terminal problem. ◦ Reserve the time slots with the same priority. ◦ Continuous reservation collisions. ◦ Non-Cooperative connections. ◦ Some nodes may not get time slots. ◦ Less overall throughput. ◦ Markov chain model can not be implemented. ◦ Network intelligence is not possible. In one scenario, Station A can communicate with Station B. Station C can also communicate with Access Point Station B. However, Stations A and C cannot communicate with each other as they are out of range of each other.
  5. 5. Contd…  Advantages of Game-Based MAC protocol ◦ Assigns priority to nodes. ◦ Time slot reservation based on priority. ◦ Priority decided based on waiting counter ◦ Analysis can be done using Markov chain. ◦ Provides colliding nodes two strategies to reserve new time slots • Reserving the original conflicting slots again • Choose new idle slots to reserve
  6. 6. System Model  Each vehicle has its own ID ◦ ID ∈ {1, 2, ・ ・ ・,N} for N vehicle  Initial position of vehicles are random.  Transmission range of each vehicle is r(assigned by system)  All the vehicles have GPS.  The neighboring nodes are of two types ◦ One-hop nodes ◦ Two-hop nodes  One-hop sets (OHSs) and two-hop sets (THSs) are defined as the sets of nodes whose relative distance is shorter than the communication range r or 2r.  THS = OHS1 U OHS2 .
  7. 7. Contd…  For a node x, ◦ N(x) - set of IDs of one-hop neighbours of node x. ◦ S(x) - set of time slots where node x cannot reserve.  Transmission collisions are of two types ◦ Access collision : when two or more nodes reserve the same time slot when they are in the same THS. ◦ Merging collision : when two nodes communicate with another node in a two-hop set .
  8. 8. Game-Based Slot Reservation Mechanism  The Structure of Control Message and Frame ◦ Nodes reserve slots on a unique control channel. ◦ Control channel is used to broadcast control messages(vehicles’ position, speed, moving direction, the occupied slot number). ◦ Control channel is also used to transmit high-priority messages. M – no. of slots in frame 𝑀 𝑎- no. traditional time slots L – no. of special slots(0,M/2) 𝑀 𝑎=M – L
  9. 9. Contd…  Two types of time slots :- ◦ Traditional time slots(𝑀 𝑎) - This let those occupied slots’ nodes broadcast the control messages periodically or let the nodes that need to reserve slots broadcast the reservation message. ◦ Special Slots(L) - This let those colliding nodes reserve slots again.  The broadcasting sequence in the special slots is arranged according to the number of the conflicting slots.  Number of special nodes depends on the node density in the network.  This slot arrangement reduces the total number of slots for reserving, but it does increase the success rate of reservation, and the total number of occupied slots is increased in the high-density network.
  10. 10. Contd… Fig 2. The structure of control message • Modifications in control message • Slot Information – Records the status of slots. • Waiting Counter(W(x)) - record the total times that node x chooses to reserve a new slot after the reservation collision happens. • The value of W(x) is a number, it just occupies 8 bits which is much less than the payload data.
  11. 11. The Reservation Procedure  Information Synchronization ◦ When a new node joins to the network it has to monitor at least one frame to collect control messages from other nodes. ◦ Then it updates following sets :  𝑁(𝑥) – Set of one-hop neighbours of x.  𝑆 𝑜ℎ𝑠 𝑥 − Set of time slots occupied by one-hop neighbours of x.  𝑊𝑜ℎ𝑠 𝑥 −Set of waiting count of one-hop neighbours of x.  𝑆𝑡ℎ𝑠 𝑥 − Set of time slots occupied by two-hop neighbours of x.  𝑊𝑡ℎ𝑠 𝑥 − Set of waiting count of two-hop neighbours of x.  𝑆 𝑥 = 𝑆 𝑜ℎ𝑠(𝑥) ∪ 𝑆𝑡ℎ𝑠 (𝑥)  𝑊 𝑥 = 𝑊𝑜ℎ𝑠(𝑥) ∪ 𝑊𝑡ℎ𝑠 (𝑥)
  12. 12. Contd…  Available Slots Reservation ◦ A node x can choose any slot k for reservation from available set. ◦ Changes mark of slot k from 0 to 1. ◦ Update the set N(x). ◦ Broadcast updated control message. ◦ Node x will monitor the control message one frame after reservation. ◦ The reservation will end only when the node x and its neighbours have updated the related sets.
  13. 13. Contd…  Slot Allocation
  14. 14. Contd…  The Collision Judgement ◦ The reservation collision is of two types:  Access collision  Merging collision ◦ Both of them are the collision that two or more nodes within two-hop range acquired the same slot. ◦ When a reservation collision occurs the slot broadcasts a notice message. ◦ The notice is like a urgent notice to all other nodes in network.
  15. 15. Contd…  The Time Slot Competition Game ◦ When the collision happens both the nodes have to play the game. ◦ According to the game theory the strategy status of nodes are{R,W}  R indicates that colliding nodes reserve the original slot again.  W indicates that colliding nodes choose another slot to reserve. ◦ The colliding nodes will choose the strategy R or W according to the probability calculated through the game. ◦ There are three different cases for the colliding nodes according to the strategy. In each case Utility value is calculated. ◦ Utility values are the probabilities of the nodes getting the slot under a particular case.
  16. 16. Contd…  Example of Time–Slot Competition Game ◦ Let there are v colliding nodes.[ I = {1,2,…,v} ] ◦ The three cases for node i  If node i reserves the original slot again and other colliding nodes gives up reserving the original slot, it will occupy the time slot successfully, in this case, the utility value is 𝑢𝑖 𝑟 .  if node i reserves the original slot again and there exists other colliding nodes reserve the original slot, it fails to occupy the time slot, in this case, the utility value is 𝑢𝑖 𝑐 .  if node i chooses a new slot to reserve, it won’t affect other colliding nodes reserve the original slot, in this case, the utility value is 𝑢𝑖 𝑤 . ◦ The larger the waiting count of a node , the higher priority is given to it.
  17. 17. Contd…  𝑈𝑖: The utility function of node i.  ϕ(v): The probability that the slot is reserved successfully in v-points game.  𝑃𝑖: The probability that node i chooses the strategy R  The utility value of node i is  Calculating partial derivative of (1)  Substitute 𝑃𝑗 = 1 − 𝑃𝑖 in (2)  (3) gives the Nash equilibrium solution or the probability set of nodes choosing the strategy R.
  18. 18. Contd…  Extending 2-point model to v-point model the equations will be
  19. 19. Performance Analysis  Assumptions before analysis ◦ All the nodes are in the same THS; ◦ All the nodes remain still in one frame; ◦ Any node i has updated N(i), S(i),W(i) before reserving the slots.  The Distribution of chosen slots  Calculate the lower bound and the upper bound
  20. 20. Simulation Result And Analysis Fig 4. The simulation result compared with the theoretical upper and lower bound. Fig 5. The reservation speed of GAH-MAC compared with VeMAC
  21. 21. Contd… Fig 6. The performance of normalized throughput in the city scenario. Fig 7. The performance of packet drop rate in the city scenario.
  22. 22. Conclusion  This presents a GAH-MAC protocol.  This protocol sacrifices part of the available slots as special slots. The colliding nodes play games with each other to decide whether to reserve the original slot or a new one, and use the special slots to broadcast messages.  The success rate for a reservation is increased, and fairness in the reservation of nodes is ensured by a new modular waiting counter.  The reservation speed, throughput performance, and packet drop rate are simulated and compared with those of the VeMAC protocol.  The simulation results show that the performance of GAH-MAC is superior to VeMAC in high-density networks.  GAH-MAC decreases the packet drop rate and increases network throughput.
  23. 23. References 1. K. Mehta, L. G. Malik, and P Bajaj, “VANET: Challenges, issues and solutions,” in Proc. IEEE ICETET, 2013, pp. 78–79. 2. Standard for Information Technology-Tele-communications and Information Exchange between Systems-Local and Metropolitan Area Networks- Specific Requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, IEEE Std 802.11-2007, June 2007. 3. Standard for Information Technology-Tele-communications and Information Exchange between Systems-Local and Metropolitan Area Networks- Specific Requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications Amendment 6: Wireless Access in Vehicular Environments, IEEE Std 802.11p-2010, July 2010. 4. M. Hassan, H. Vu, and T. Sakurai, “Performance analysis of the IEEE 802.11 MAC protocol for DSRC safety applications,” IEEE Trans. Veh. Technol., vol. 60, no. 8, pp. 3882–3896, Oct. 2011. 5. F. Borgonovo, A. Capone, M. Cesana, and L. Fratta, “ADHOC MAC: New MAC architecture for Ad Hoc networks providing efficient and reliable point-to- point and broadcast services,” Wireless Netw., vol. 10, no. 4, pp. 359–366, July 2004. 6. H. A. Omar, W. Zhuang, and L. Li, “VeMAC: A TDMA-based MAC protocol for reliable broadcast in VANETs,” IEEE Trans. Mobile Comput., vol. 12, no. 9, pp. 1724–1736, Sept. 2013. 7. Z. Yang, Y.-D. Yao, X. Li, and D. Zheng, “A TDMA-based MAC protocol with cooperative diversity,” IEEE Commun. Lett., vol. 14, no. 6, pp. 542–544, 2010. 8. S. Bharati and W. Zhuang, “CAH-MAC: Cooperative ADHOC MAC for vehicular networks,” IEEE J. Sel. Areas Commun., vol. 31, no. 9, pp. 470–479, Sept. 2013.
  24. 24. 9. J.-K. Lee, H.-J. Noh, and J. Lim, “TDMA-based cooperative MAC protocol for multi-hop relaying networks,” IEEE Commun. Lett., vol. 18, no. 3, pp. 435–438, Mar. 2014. 10. D. N. Dang, H. N. Dang, V. Nguyen, Z. Htike, and C. S. Hong, “HERMAC: A hybrid efficient and reliable MAC for vehicular ad hoc networks,” in Proc. IEEE AINA, May 2014, pp. 186–193. 11. R. Zou, Z. Liu, L. Zhang, and M. Kamil, “A near collision free reservation based MAC protocol for VANETs,” in Proc. IEEE WCNC, Istanbul, Turkey, pp. 1538–1543, Apr. 2014. 12. L. Zhang, Z. Liu, R. Zou, J. Guo, and Y. Liu, “A scalable SCMA and selforganzing TDMA MAC for IEEE 802.11 p/1609.x in VANETs,” Wireless Pers. Commun., vol. 74, no. 4, pp. 1197–1212, Feb. 2014. 13. W. Ding, J.Wang, Y. Li, P.Mumford, and C. Rizos, “Time synchronization error and calibration in integrated GPS/INS systems,” ETRI J., vol. 30, no. 1, pp. 59– 67, 2008. 14. W. Franz, H. Hartenstein, and M. Mauve, Inter-Vehicle Communications Based on Ad Hoc Networking Principles: The FleetNet Project, Universitatsverlag Karlsruhe, 2005. 15. F. Borgonovo, L. Campelli, M. Cesana, and L. Fratta, “Impact of user mobility on the broadcast service efficiency of the ADHOC MAC protocol,” in Proc. IEEE VTC, June 2005. 16. R. Gibbons, A Primer in Game Theory, China Social Science Press, 1999.
  25. 25. Thank you

×