1. Mobile Networks and Applications (January 2007) Presented by J.H. Su ( 蘇至浩 ) 2016/3/21 OPLab, IM, NTU 1 Joint Design of Routing and Medium Access Control for Hybrid Mobile Ad Hoc Networks

2. Authors(1/2) 2016/3/21 OPLab, IM, NTU 2 Xiaojiang (James) Du Received the Ph.D. degrees from University of Maryland College Park in electrical engineering. An Assistant Professor with the Department of Computer Science, North Dakota State University, Fargo. His research interests are wireless sensor networks, mobile ad hoc networks, wireless networks, computer networks, network security, and network management.

3. Authors(2/2) 2016/3/21 OPLab, IM, NTU 3 Dapeng Wu Received the Ph.D. degree in electrical and computer engineering from Carnegie Mellon University, Pittsburgh, PA, in 2003. Has been with Electrical and Computer Engineering Department, University of Florida, Gainesville, as an Assistant Professor. His research interests are in the areas of networking, communications, multimedia, signal processing, and information and network security.

4. Agenda 2016/3/21 OPLab, IM, NTU 4 Introduction Assumption of HR Hybrid Routing Protocol Performance Evaluation Conclusion

5. Agenda 2016/3/21 OPLab, IM, NTU 5 Introduction Assumption of HR Hybrid Routing Protocol Performance Evaluation Conclusion

6. Introduction (1/2) 2016/3/21 OPLab, IM, NTU 6 Most existing routing protocols assume homogeneous MANETs. Gupta and Kumar showed that per node capacity of a homogeneous wireless network is only w/√ (nlogn) W is the node transmission capacity n is the number of nodes

7. Introduction (2/2) 2016/3/21 OPLab, IM, NTU 7 Furthermore, in many realistic ad hoc networks, nodes are hybrid. in a battlefield network In this paper, we present a new routing protocol—Hybrid Routing (HR) protocol for hybrid MANETs. node location information is used to reduce routing overhead

8. Agenda 2016/3/21 OPLab, IM, NTU 8 Introduction Assumption of HR Hybrid Routing Protocol Performance Evaluation Conclusion

9. Assumption of HR (1/2) 2016/3/21 OPLab, IM, NTU 9 For simplicity, we consider there are only two types of nodes in the network. Backbone-Capable nodes general nodes The main idea of HR protocol is to let most routing activities rely on B-nodes. provides better reliability and fault tolerance routing packets via B-nodes is more efficient than using general nodes reduces the routing overhead and latency

10. Assumption of HR (2/2) 2016/3/21 OPLab, IM, NTU 10 The routing area is divided into several small, equal-sized squares—referred to as cells. In HR protocol, we assume the routing area is fixed. the position of each cell is also fixed There is a unique id for each cell. One (and only one) B-node is elected and maintained in each cell, and each B- node has a second address. B-node can always communicate directly with B-nodes in all nearby cells.

11. Agenda 2016/3/21 OPLab, IM, NTU 11 Introduction Assumption of HR Hybrid Routing Routing among B-nodes Route Discovery Route Repair Dissemination of Node Location Information Election of B-node Hybrid MAC (HMAC) Performance Evaluation Conclusion

12. Routing among B-nodes (1/2) 2016/3/21 OPLab, IM, NTU 12 B-nodes use their second addresses to communicate with each other. A straight line L is drawn between the centers of cell C S and C d. Two border lines (blue lines) which parallel to line L with distance of W from L are drawn from C S to C d. the value of W depends on the density of BC-nodes in the network All the cells that are within the two border lines are defined as routing cells.

13. Routing among B-nodes (2/2) 2016/3/21 OPLab, IM, NTU 13 WW

14. Agenda 2016/3/21 OPLab, IM, NTU 14 Introduction Assumption of HR Hybrid Routing Routing among B-nodes Route Discovery Route Repair Dissemination of Node Location Information Election of B-node Hybrid MAC (HMAC) Performance Evaluation Conclusion

15. Route Discovery (1/4) 2016/3/21 OPLab, IM, NTU 15 Consider a node S wants to send a data packet to a destination node D. Case 1 : S is a B-node Case 2 : S is a general node S needs to know the current location of the destination node D. Then S determines the routing cells between S and B d, and sends Route Request (RR) packets to B-nodes in routing cells.

16. Route Discovery (2/4) 2016/3/21 OPLab, IM, NTU 16 The RRpacket includes the following fields: Starting_B-node Next_cells Routing_cells Path Destination_cell

17. Route Discovery (3/4) 2016/3/21 OPLab, IM, NTU 17 12 3 4 567 8 91012 131416 11 S D

18. Route Discovery (4/4) 2016/3/21 OPLab, IM, NTU 18 If S does not receive a RP from B s for a certain time: S will initiate a B-node elecion If B s does not receive a RP from B d for a certain time: B s will flood the RR packet to all B-nodes in the network If B d does not receive the Ack for a certain time B d will hold the data packet (before receiving Ack) and request the updated location information of node D then B d can send the data packet to the B-node closest to the new location of D

19. Agenda 2016/3/21 OPLab, IM, NTU 19 Introduction Assumption of HR Hybrid Routing Routing among B-nodes Route Discovery Route Repair Dissemination of Node Location Information Election of B-node Hybrid MAC (HMAC) Performance Evaluation Conclusion

20. Route Repair (1/2) 2016/3/21 OPLab, IM, NTU 20

21. Route Repair (2/2) 2016/3/21 OPLab, IM, NTU 21 The RE packet includes the following fields: Repairing_B-node Next_cell Routing_cells Destination_cell Destination_ node Path

22. Agenda 2016/3/21 OPLab, IM, NTU 22 Introduction Assumption of HR Hybrid Routing Routing among B-nodes Route Discovery Route Repair Dissemination of Node Location Information Election of B-node Hybrid MAC (HMAC) Performance Evaluation Conclusion

23. Dissemination of Node Location Information 2016/3/21 OPLab, IM, NTU 23 When a node moves out of its previous cell, it sends a location update packet (with its new location) to the B- node in the new cell (or the nearest B-node). All B-nodes periodically send aggregated node location information to a special B-node B 0. If B 0 also moves around, then B 0 needs to multicast its current location to all B-nodes

24. Agenda 2016/3/21 OPLab, IM, NTU 24 Introduction Assumption of HR Hybrid Routing Routing among B-nodes Route Discovery Route Repair Dissemination of Node Location Information Election of B-node Hybrid MAC (HMAC) Performance Evaluation Conclusion

25. Election of B-node (1/2) 2016/3/21 OPLab, IM, NTU 25 Initially, one B-node is elected in each cell if there are BC- nodes available in the cell. Following events Initiates the B-node election process: a B-node moves out of its current cell a general node discovers there is no B-node in the cell

26. Election of B-node (2/2) 2016/3/21 OPLab, IM, NTU 26 The election process works as following: the leaving B-node or the general node floods an election message to all the nodes in the cell when a BC-node receives the election message, it broadcasts a claim message that claims it will become the B-node to all nodes in the cell (each BC-node defers a random time before its B-node claim) if other BC-node hears a claim message during this random time, it then gives up its broadcast.

27. Agenda 2016/3/21 OPLab, IM, NTU 27 Introduction Assumption of HR Hybrid Routing Routing among B-nodes Route Discovery Route Repair Dissemination of Node Location Information Election of B-node Hybrid MAC (HMAC) Performance Evaluation Conclusion

28. Hybrid MAC (1/2) 2016/3/21 OPLab, IM, NTU 28 The key idea is to combine time-slotted mechanism with contention based mechanism. A large time frame is divided into three sub-frames G-to-G B-to-B B-to-G

29. Hybrid MAC (2/2) 2016/3/21 OPLab, IM, NTU 29 Inside each sub-frame, the corresponding nodes use contention-based mechanism— IEEE 802.11b to decide which node should transmit packets. The sub-frame length depends on the amount of traffic of each subtype.

30. Agenda 2016/3/21 OPLab, IM, NTU 30 Introduction Assumption of HR Hybrid Routing Protocol Performance Evaluation Experiment Setting Routing overhead under different mobility Routing overhead vs. transmission range Throughput under different traffic load Delay comparison Scalability The performance of HMAC The probability of having B-nodes Performance for different BC-node densities Conclusion

31. Experiment Setting(1/3) 2016/3/21 OPLab, IM, NTU 31 there are totally 20 time-slots G-to-G sub-frame takes eight timeslots B-to-B sub-frame takes eight time-slots B-to-G sub-frame takes four time-slots we present the simulations performed by distributing 100 nodes uniformly at random in an area of 1,000×1,000 m. 25 Backbone-Capable (BC) nodes 75 General nodes

32. Experiment Setting(2/3) 2016/3/21 OPLab, IM, NTU 32 The transmission range of a B-node and a general node is 400 and 100 m. The side length of a cell is set as a=R/1.6. There are 16 cells in the routing area The width of the routing cells—W is set to 0

33. Experiment Setting(3/3) 2016/3/21 OPLab, IM, NTU 33 Each simulation was run for 600 simulated seconds. The source sent packet of 512 b at a rate of four packets per second. We ran each simulation ten times to get an average result for each simulation configuration. We compared our HR protocol with AODV (Ad-hoc on demand distance vector) routing protocol.

34. Agenda 2016/3/21 OPLab, IM, NTU 34 Introduction Assumption of HR Hybrid Routing Protocol Performance Evaluation Experiment Setting Routing overhead under different mobility Routing overhead vs. transmission range Throughput under different traffic load Delay comparison Scalability The performance of HMAC The probability of having B-nodes Performance for different BC-node densities Conclusion

35. Routing overhead under different mobility 2016/3/21 OPLab, IM, NTU 35

36. Agenda 2016/3/21 OPLab, IM, NTU 36 Introduction Assumption of HR Hybrid Routing Protocol Performance Evaluation Experiment Setting Routing overhead under different mobility Routing overhead vs. transmission range Throughput under different traffic load Delay comparison Scalability The performance of HMAC The probability of having B-nodes Performance for different BC-node densities Conclusion

37. Routing overhead vs. transmission range 2016/3/21 OPLab, IM, NTU 37

38. Agenda 2016/3/21 OPLab, IM, NTU 38 Introduction Assumption of HR Hybrid Routing Protocol Performance Evaluation Experiment Setting Routing overhead under different mobility Routing overhead vs. transmission range Throughput under different traffic load Delay comparison Scalability The performance of HMAC The probability of having B-nodes Performance for different BC-node densities Conclusion

39. Throughput under different traffic load 2016/3/21 OPLab, IM, NTU 39

40. Agenda 2016/3/21 OPLab, IM, NTU 40 Introduction Assumption of HR Hybrid Routing Protocol Performance Evaluation Experiment Setting Routing overhead under different mobility Routing overhead vs. transmission range Throughput under different traffic load Delay comparison Scalability The performance of HMAC The probability of having B-nodes Performance for different BC-node densities Conclusion

41. Delay comparison 2016/3/21 OPLab, IM, NTU 41

42. Agenda 2016/3/21 OPLab, IM, NTU 42 Introduction Assumption of HR Hybrid Routing Protocol Performance Evaluation Experiment Setting Routing overhead under different mobility Routing overhead vs. transmission range Throughput under different traffic load Delay comparison Scalability The performance of HMAC The probability of having B-nodes Performance for different BC-node densities Conclusion

43. Scalability 2016/3/21 OPLab, IM, NTU 43 HR-S HR-L AODV-S AODV-L

44. Agenda 2016/3/21 OPLab, IM, NTU 44 Introduction Assumption of HR Hybrid Routing Protocol Performance Evaluation Experiment Setting Routing overhead under different mobility Routing overhead vs. transmission range Throughput under different traffic load Delay comparison Scalability The performance of HMAC The probability of having B-nodes Performance for different BC-node densities Conclusion

45. The performance of HMAC - Throughput 2016/3/21 OPLab, IM, NTU 45

46. The performance of HMAC - Delay 2016/3/21 OPLab, IM, NTU 46

47. Agenda 2016/3/21 OPLab, IM, NTU 47 Introduction Assumption of HR Hybrid Routing Protocol Performance Evaluation Experiment Setting Routing overhead under different mobility Routing overhead vs. transmission range Throughput under different traffic load Delay comparison Scalability The performance of HMAC The probability of having B-nodes Performance for different BC-node densities Conclusion

48. Performance for different BC-node densities 2016/3/21 OPLab, IM, NTU 48

49. Agenda 2016/3/21 OPLab, IM, NTU 49 Introduction Assumption of HR Hybrid Routing Protocol Performance Evaluation Conclusion

50. 2016/3/21 OPLab, IM, NTU 50 Proposed Hybrid Routing Protocol to resolve routing problem in different type of node. An efficient algorithm is provided to disseminate node location information among all B-nodes. Proposed a novel HMAC protocol that can improve the efficiency of medium access in hybrid MANETs.

51. Conclusion 2016/3/21 OPLab, IM, NTU 51 HR has very good performance, and performs much better than AODV in terms of reliability, scalability, route discovery latency, routing overhead as well as packet delay and throughput.