1. MR2RP: The Multi-Rate and Multi-Range Routing Protocol for IEEE 802
MR2RP: The Multi-Rate and Multi-Range Routing Protocol for IEEE Ad Hoc Wireless Networks
SHIANN-TSONG SHEU
Department of Electrical Engineering, Tamkang University, Tamsui, Taipei, Taiwan, ROC
YIHJIA TSAI and JENHUI CHEN
Department of Computer Science and Information Engineering, Tamkang University, Tamsui, Taipei, Taiwan, ROC
Wireless Networks 9, 165–177, 2003
Presented by Yeong-cheng Tzeng

2. Outline Introduction The IEEE 802.11 MAC protocol
The multi-rate and multi-range routing in multi-hop ad hoc WLANs
Simulation model and results
Conclusion

3. 1. Introduction Wireless services become ever more ubiquitous
An increasing demand for the provision of the multimedia services
Contention-based MAC protocol cannot guarantee transfer delay for multimedia services
In multi-hop ad hoc networks
how to find a reliable route with delay constrain
PCF is not designed for the distributed environment
In multi-rate/multi-range wireless ad hoc network
The maximal data rate is adopted to the transmission distance
The shortest path of minimal hops may not be the fast route
Propose MR2RP to maximize channel utilization as well as the transfer delay

4. 2. The IEEE MAC protocol
The DCF defined an optionally four-way handshaking scheme (RTS/CTS)
To overcome the hidden terminal problem
To provide virtual carrier sense (NAV) for saving battery power

5. 3. The multi-rate and multi-range routing in multi-hop ad hoc WLANs
3.2. The multi-rate and multi-range transmission model
3.3. The multi-rate and multi-range routing protocol (MR2RP)
3.4. The MAC delay estimation
3.5. The buffer queuing delay estimation
3.6. The routing protocol

6. 3.1. Multi-hop ad hoc WLANs
How to find an efficient and reliable route?
Shortest-path routing – distributed Bellman-Ford
Measurement of distance
Number of hops
Delay time

7. 3.2. The multi-rate and multi-range transmission model
Tradeoff between utilization and speed
A longer hopping will shorten the transmission distance
Sacrifice the transmission speed
Choose the path of the maximal transmission rate to minimize the transfer delay
Increase the contention delay and buffer delay
Degrade the throughput

8. 3.3. The multi-rate and multi-range routing protocol (MR2RP)
Problems must be solved
Collect all network information on time
DSR – flooding with route-discovery packets
AODV – hybrid on-demand and table-driven routing
Predict the precise MAC delay of a MH
Estimates the precise transmission cost

9. 3.3. The multi-rate and multi-range routing protocol (MR2RP)
Connectivity matrix
where

10. 3.4. The MAC delay estimation

11. 3.4. The MAC delay estimation
Poisson distribution

12. 3.4. The MAC delay estimation
Arrival state

13. 3.4. The MAC delay estimation
Backoff state

14. 3.4. The MAC delay estimation
Expected backoff defer

15. 3.4. The MAC delay estimation
NAV state
Expected NAV defer

16. 3.4. The MAC delay estimation
Backoff state delay
NAV state delay

17. 3.4. The MAC delay estimation

18. 3.4. The MAC delay estimation
Final result

19. 3.5. The buffer queuing delay estimation
Minimal MAC access delay
May not be the best path of the minimal end-to-end transfer delay
The buffer delay may dominate the transfer delay
Need for the buffer information

20. 3.6. The routing protocol

21. 3.6. The routing protocol MH0, MH3, MH5 MH0,MH6,MH7,MH5
=10.01
MH0,MH6,MH7,MH5
=8.82
MH3 is a bottleneck

22. 4. Simulation model and results
Scenario
16 mobile hosts active in a square area of 200m x 200m
Model I
Hosts are static
Model II
Hosts are movable
Investigate four parameter
Average transfer delay
Average MAC access delay
Call blocking probability
Packet loss ratio

23. 4. Simulation model and results

24. 4. Simulation model and results

25. 4. Simulation model and results

26. 4. Simulation model and results

27. 5. Conclusion Present a new routing protocol MR2RP Simulation results
MAC delay is estimated precisely
Find the fast path according to MAC delay, transmission delay and buffer queuing delay
Simulation results
Reduce the total transfer delay
Increase the total amount of serviced packets
The packet loss ratio caused by mobility can be also improved

28. The End