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SEMINAR REPORT on Adaptive Routing in Adhoc Networks - Mayuri Padhye - 08-17-2017 SEMINAR REPORT on Adaptive Routing in Adhoc Networks Submitted in partial fulfillment for the award of the degree of Master of Technology in Computer and Information Science By M.VENGATACHALAM Department of Computer Science Cochin University of Science and Technology Cochin-22, Kerala 2008 Page 2 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 2 COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY DEPARTMENT OF COMPUTER SCIENCE CERTIFICATE This is to certify that the report entitled Adaptive Routing in Adhoc Networks is a bonafide record of the seminar presented by Mr.M.VENGATACHALAM. in partial fulfillment of the requirements for the award of M.Tech Degree in Computer and Information Science of Cochin University of Science & Technology, during the academic year 2008. G. Santhosh Kumar Prof. Dr. K. Poulose Jacob Lecturer Head of the Department Seminar Guide Dept of Computer Science Dept of Computer Science CUSAT CUSAT Kochi-22 11-07-2008 Page 3 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 3 ACKNOWLEDGEMENT First of all, I thank GOD ALMIGHTY, for showering his grace upon me to successfully carry out this work, everything in time. I take this opportunity to thank Prof. Dr. K. Poulose Jacob, Head of the Dept. of Computer Science, CUAST for providing me with the necessary facilities to do this work. I am deeply indebted to Shri.G. Santhosh Kumar, Lecturer, Dept. of Computer Science, CUSAT for the excellent guidance and timely suggestions. Finally, I express my deepest gratitude to all my family members for their encouragement, which helped me to keep my spirit alive and complete this work successfully. M.VENGATACHALAM Page 4 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 4 ABSTRACT The dynamics of an ad hoc network are a challenge to protocol design because mobility inevitably leads to unstable routing, and consequently flows encounter fluctuations in resource availability on various paths during the lifetime of a session. This has become serious, especially for those protocols based on single-path reservation, as frequent reservation and restoration of reservation-based flows increase the instability of connections. Advances in wireless research are focusing more and more on the adaptation capability of routing protocols due to the interrelationship among various performance measures such as those related to topological changes (link breakages, node mobility, etc.) and quality of service (QoS) parameters (load, delay, etc). After giving a more detailed discussion of the existing work in adaptive routing, we propose a new routing protocol for adhoc wireless networks - Multipath Source Routing (MSR), which is an extension of DSR(Dynamic Source Routing) that incorporates the multipath mechanism into DSR. Based on the measurement of RTT(Round Trip Time), we propose a scheme to distribute load among multiple paths. MSR is an adaptive routing for ad hoc networks. It considers the two fundamental issues in its design. MSR may adapt to topology changes by retaining the route discovery and route maintenance mechanism of DSR. In addition, MSR employs a probing-based load-balancing mechanism. Simulation results show that MSR can improve the packet delivery ratio and the throughput of TCP and UDP, and it reduces the end-to-end delay and the average queue size while adding little overhead. As a result, MSR decreases network congestion and increases the path fault tolerance quite well. Page 5 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 5 TABLE OF CONTENTS Page No. CHAPTER 1 : INTRODUCTION 7 1.1 Introduction 7 1.2 Adaptive Routing 7 1.3 Adhoc Networks 8 CHAPTER 2 : NETWORK ARCHITECTURES 10 2.1 Infrastructure Based Networks 10 2.2 Rapidly Deployable Network 11 2.3 Hybrid Networks 12 CHAPTER 3 : ROUTING PROTOCOLS 13 3.1 Introduction 13 3.2 Proactive routing protocols(Table Driven) 13 3.3 Reactive routing protocols(On demand protocols) 13 3.4 Hybrid routing protocols 13 CHAPTER 4 : DYNAMIC SOURCE ROUTING CHAPTER 5 : MSR (MULTIPLE SOURCE ROUTING) 14 5.1 Introduction 14 5.2 Route Discovery 14 5.3 Route Maintenance 19 5.4 Path finding 19 5.5 Packet forwarding and load balancing 19 5.6 Toward gratuitous mode 21 CHAPTER 6 : PERFORMANCE EVALUATION 22 6.1 Simulation environment 22 6.2 Performance Metrics 22 6.3 Simulation Results 22 6.3.1 UDP traffic (max moving speed of 20 m/s) 22 6.3.2 TCP traffic (max- moving speed 20m/s) 26 Page 6 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 6 CHAPTER 7 : DISCUSSIONS 27 CHAPTER 8 : CONCLUSIONS 30 APPENDIX (LIST OF FIGURES & TABLES) 31 REFERENCES 33Page 7 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 7 CHAPTER 1 INTRODUCTION 1.1 Introduction Congestion at the links and in the routers is the main cause of large delays in the Internet; the same is true in ad hoc networks where bandwidths are always very limited. Routing protocols used in conventional wired networks (e.g., Bellman-Ford and page link state) are not well suited for the mobile environment due to the considerable overhead produced by periodic route update messages, and to their slow convergence to topological changes. In addition, all the Internet routing protocols in use today rely on single-path routing algorithms, which not only under-utilize resources, but also cannot cope with congestion and page link breakage. This can be attributed to the fact that all traffic for a destination is required to be routed through a single successor. So when a page link becomes congested or broken, its entire carried traffic has to be rerouted; this becomes more time consuming in mobile networks. If page link costs are made functions of congestion or delays, routing table entries can become unstable in single-path routing protocols. Before get in to details we will discuss about the Adaptive routing and Adhoc networks. 1.2 Adaptive routing Adaptive routing describes the capability of a system, through which routes are characterised by their destination, to alter the path that the route takes through the system in response to a change in conditions. The adaptation is intended to allow as many routes as possible to remain valid (that is, have destinations that can be reached) in response to the change. The term is commonly used in data networking to describe the capability of a network to 'route around' damage, such as loss of a node or a connection between nodes, so long as other path choices are available. There are several protocols used to achieve this. Systems that do not implement adaptive routing are described as using static routing, where routes through a network are described by fixed paths (statically). A change, such as the loss of a node, or loss of a connection between nodes, is not compensated for. This means that anything that wishes to take an affected path will either have to wait for the failure to be repaired before restarting its journey, or will have to fail to reach its destination and give up the journey. Page 8 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 8 1.3 Adhoc Networks An ad-hoc (or "spontaneous") network is a local area network or other small network, especially one with wireless or temporary plug-in connections, in which some of the network devices are part of the network only for the duration of a communications session or, in the case of mobile or portable devices, while in some close proximity to the rest of the network. In Latin, ad hoc literally means "for this," further meaning "for this purpose only," and thus usually temporary and does not require a router or a wireless base station. Fig 1.1 represent the Adhoc networks. . Multipath routing can overcome the above problem discussed in 1.1. In addition, it can provide load balancing and route failure protection by distributing traffic among a set of diverse paths. These benefits make multipath routing a good candidate for bandwidth limited and mobile ad hoc networks. However, maintaining alternative paths requires much more routing table space and computation, especially for table-driven routing algorithms in large networks. Fig 1.1 Adhoc networks Many adhoc routing protocols have been proposed recently, such as AODV, DSDV, DSR, and TORA. However, they are all single-path based . DSR (DynamicPage 9 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 9 Source Routing) is capable of reducing communication and computation overhead. In this work, the analytical models have been developed to demonstrate how the frequency of query floods is reduced with their multipath extensions, and presented some numerical data obtained from the analytic models. They also did some simple and preliminary simulations; there are still a lot of work regarding multipath routing in wireline networks. In this paper, we propose a new approach called the Multipath Source Routing (MSR) for multipath routing in ad hoc wireless networks. This is an extension of DSR (Dynamic Source Routing). Our work focuses on the adaptively distributing load among several paths, according to the measurement of the round-trip time of every path, whereby a heuristic load balancing equation is given. To the best of our knowledge, this is the first trial to introduce probing-based feedback control to multipath routing. An RTT measurement tool for DSR and MSR in simulation, SRping is developed to get the RTT between two arbitrary nodes. It is also the first attempt to analyze the TCP dynamics in ad hoc networks and multipath routing context. Our results show that MSR can reduce the traffic burst ness seen by individual paths, adapt to frequently topology changes and consequently achieve inherent robustness to channel errors and page link failures. We also analyze and compare the packet dynamics of MSR and DSR in depth. Page 10 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 10 CHAPTER 2 NETWORK ARCHITECTURES There are different types of wireless networks are being used across for various communication. They are 1. Infrastructure based networks 2. Rapidly deployable networks 3. Hybrid Networks 2.1 Infrastructure Based Networks Infrastructure networks contain special nodes called access points(APs), which are connected via existing networks. APs are special in the sense that they can interact with wireless nodes as well as with the existing wired network. The other wireless nodes, also known as mobile stations(STAs), communicate via APs. The APs also act as bridges with other networks. Fig 2.1 shows the infrastructure networks. Example for infrastructure network is Cellular network and Sattelite network. Page 11 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 11 Fig.2.1 Infrastructure network 2.2 Rapidly deployable network In Ad Hoc Mode, chains of computers will connect to pass your data, if your computer is not directly in range. On the other hand, you do not have control over the path your data takes. The automatic configuration routines may send your data through several computers, causing significant network delays. changes regularly, system resources are taken just to maintain connectivity. Because Ad Hoc Mode does not require an access point, it's easier to set up, especially in a small or temporary network. Infrastructure takes advantage of the high power of an access point to cover wide areas. Ad Hoc Mode connections are limited, for example between two laptops, to the power available in the laptops. Because the network layout (the network topology) in Ad Hoc Mode As the Ad Hoc topology changes, throughput and range will change, sometimes in unanticipated ways. New users will have an easier time learning wireless strengths and weaknesses with Infrastructure Mode, and therefore the NETGEAR Installation Guides focus on it. In an Ad Hoc network with many computers, the amount of interference for all computers will go up, since each is trying to use the same frequency channel. Page 12 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 12 Fig 2.2 shows the scenario. The example for Rapidly deployable networks are a) Adhoc wireless networks b) Wireless sensor networks c) Heterogeneous networks Fig.2.2 Rapidly Deployable Network 2.3 Hybrid Network One of the major application areas of ad hoc wireless networks is in hybrid wireless architectures such as multi-hop cellular networks and an integrated cellular adhoc relay networks. The primary concept behind the cellular networks is geographical channel reuse. Several techniques such as cell sectoring, cell resizing, and multi-tier cells have been proposed to increase the capacity of cellular networks. This is the combination of both infrastructure and rapidly deployable networks. Wireless internet is comes under this category. Page 13 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 13 CHAPTER 3 ROUTING PROTOCOLS 3.1 Introduction A routing protocol is a protocol that specifies how routers communicate with each other to disseminate information that allows them to select routes between any two nodes on a network. Typically, each router has a prior knowledge only of its immediate neighbors. A routing protocol shares this information so that routers have knowledge of the network topology at large. Three types of routing protocols have been identified. They are a) Proactive routing protocols b) Reactive routing protocols c) Hybrid routing protocols 3.2 Proactive routing protocols(Table Driven) This type of protocols maintains fresh lists of destinations and their routes by periodically distributing routing tables throughout the network. The main disadvantages of such algorithms are - 1. Respective amount of data for maintenance. 2. Slow reaction on restructuring and failures. Examples of proactive algorithms is DSDV etc,. 3.3 Reactive routing protocols(On demand protocols) This type of protocols finds a route on demand by flooding the network with Route Request packets. Source initiates the route discovery. Example for the same is DSR(Dynamic Source routing) and MSR(Multipath Source Routing) 3.4 Hybrid routing protocols This type of protocols combines the advantages of proactive and of reactive routing. The routing is initially established with some proactively prospected routes and then serves the demand from additionally activated nodes through reactive flooding. The choice for one or the other method requires predetermination for typical cases. The main disadvantages of such algorithms are - Page 14 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 14 1. Advantage depends on amount of nodes activated. 2. Reaction to traffic demand depends on gradient of traffic volume. Example for this type of protocol is ZRP(Zone Routing Protocol) CHAPTER 4 DYNAMIC SOURCE ROUTING DSR uses source routing instead of hop-by-hop packet routing. Each data packet carries the complete path from source to destination as a sequence of IP addresses. The main benefit of source routing is that intermediate nodes need not keep route information because the path is explicitly specified in the data packet. DSR is on-demand based; that is, it does not require any kind of periodical message to be sent. The source routing mechanism, coupled with the on-demand nature of this protocol, eliminates the need for the periodic route advertisement and neighbor detection packets in other protocols. CHAPTER 5 MSR (MULTIPLE SOURCE ROUTING) 5.1 Introduction By using source routing, MSR can improve performance by giving applications the freedom to use multiple paths within the same path service. However, maintaining alternative paths requires more routing table space and computational overhead. Fortunately, some DSR s characteristics can suppress these disadvantages. First, Source Routing is so flexible that messages can be forwarded on arbitrary paths, which makes it very easy to dispatch messages to multiple paths without demanding path calculation in the intermediate hops. Second, the on-demand nature of DSR reduces the routing storage anti routing computation greatly. The MSR protocol consists of two mechanisms: Route Discovery and Route Maintenance. 5.2 Route Discovery Route discovery is initiated by a source whenever a source has a data packet to send but does not have any routing information to the destination. To establish a route, the source floods the network with request messages carrying a unique request ID. When a request message reaches the destination or a node that has route information to the destination, the node sends a route reply message containing path information back to the source. In order to reduce overhead generated during a route discovery phase, the route cache maintained at each node records routes the node has learned and overheard over Page 15 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 15 that time frame. The following fig 5.1, 5.2, 5.3, 5.3, 5.4 and 5.5 depicts the same mechanism. Fig 5.1 Route discovery in MSR Page 16 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 16 Fig 5.2 Route Discovery in MSR(contd) Page 17 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 17 Fig 5.3 Route Discovery in MSR(contd) Page 18 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 18 Fig 5.4 Route Reply in MSR Fig 5.5 Data delivery in MSR Page 19 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 19 5.3 Route Maintenance Route Maintenance is the mechanism by which the sender S of a packet detects network topology changes that render useless its route to the destination D (because two nodes listed in the route have moved out of range of each other). When Route Maintenance indicates a source route is broken, S is notified with a ROUTE ERROR packet. The sender S can then attempt to use any other route to D already in its cache or can invoke Route Discovery again to find a new route. 5.4 Path finding MSR retains the route discovery mechanism of DSR whereby multiple paths can be returned. Each route discovered is stored in the route cache with a unique route index. So it is easy for us to pick multiple paths from the cache. In multipath routing, path independence is an important property, because a more independent path set offers more aggregate physical resources between a node pair (because when those resources are not shared, the less likely the performance of one path affects the performances of other paths). To achieve high path independence, the disjoint paths are preferred in MSR. There is no looping problem in MSR, as the route information is contained inside the packet itself; routing loops, either short- or long-lived, cannot be formed as they can be immediately detected and eliminated. 5.5 Packet forwarding and load balancing Since MSR uses source routing, intermediate nodes do nothing but forwarding the packet as indicated by the route in its header, thus adding no more processing complexity than that in DSR. All the work for path calculation is done in the source hosts. In MSR, source nodes are responsible for load balancing. In our protocol, we implement a special table containing multiple path information to the specific destination, as illustrated as follows. {struct mul-dest int index ; ID Dest; float Delay; float Weight;} Dest is the destination of a route. Index is the current index of the route in DSR s route cache that has a destination to Dest. Delay is the current estimate of the round- trip time. Weight is a per-destination based load distribution weight between all the routes that have the same destination. Weight is in terms of the number of packets to be sent consecutively on the same route every time. The choice of Weight is an interesting and challenging task, and we make the following observation. Page 20 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 20 In this paper we address the multipath routing problem in the context of single channel, for the disjoint path problem in multiple channel environment Within an ad hoc network, which is always an autonomous system acting as a stub network, there is less heterogeneity in some sense when compared to WAN and MAN. For instance, in WAN or MAN the maximal bandwidths that every node can obtain vary little, so do the round- trip delays. Therefore, we assume the bandwidth-delay product is a constant. Then the available bandwidth is inversely proportional to the RTT. So the traffic can be distributed among multiple paths proportional to the available bandwidth. The principle is inherently simple but reasonable in ,wireless networks. In wireline networks, due to the very different bandwidths, delay cannot be a definite indicator of the available bandwidth. From our above observation, we propose to choose the weight Wij (i is the index of the route toj) according to a heuristic equation ( 1 ) : where is the maximum delay of all the routes to the same destination, dij is the delay of route with index i, and U is a bound to insure that Wij should not to be too large. R is a factor to control the switching frequency between routes. The larger the R s value, the less frequently the switching happens and the less processing overload of searching and positioning an entry in the mul-dest table. When choosing R, the IFQ buffer s size should also be taken into considerations. we have done extensive experiments beyond the R = 1 and we found R = 3 to be better in reducing the out-of-order deliveries in TCP. So in our experiment, R is set to three for IFQ size of 50. When distributing the load, the weighted-round-robin scheduling strategy is used. To aid the load balancing and to decouple the interlayer dependence of delay measurement, a network layer probing mechanism is employed. Probing is also an enhancement to the DSR Route maintenance mechanism. Normally, in DSR, a link breakage can be notified only when a Route Error message is returned. However, in wireless mobile environment, it has a nontrivial chance that the Route Error message cannot reach the original sender successfully. Although, as a last resort, a bit in the packet header could be included to allow a host transmitting a packet to request an explicit acknowledgement from the next hop receiver, probing one path constantly only to test its validity is not (cost effective. Therefore, the function of probing in MSR is two:fold: to get the path delay status and to test the validity of active paths. Page 21 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 21 5.6 Toward gratuitous mode We should explain gratuitous packet here. In DSR, when a data packet is received as the result of operating in promiscuous receive mode, the node checks if the Routing Header packet contains its address in the unprocessed portion of the source route. If so, the node knows that packet could bypass the unprocessed hops preceding it in the source route. The node then sends what is called a gratuitous Route Reply message to the packet s source, giving it the shorter route without these hops. Since in MSR, there are always routes that are not the shortest ones, The network stack for a mobile node consists of a page link layer (LL), an ARP module connected to LL, an interface priority queue (IFQ), a MAC layer (MAC), a networks interface (netiF), all connected to the channel. The GRAT (GRATuitous) packets increase greatly, which take too much IFQ and ARP buffer space. Thus, we turn off the gratuitous options in our simulations.Page 22 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 22 CHAPTER 6 PERFORMANCE EVALUATION 6.1 Simulation environment We use ns to conduct the simulation. CMU has extended ns with some wireless supports, including new elements at the physical, link, and routing layers of the simulation environment. Using these elements, it is possible to construct detailed and accurate simulations of wireless subnets, LANs, or multi-hop ad hoc networks. For scenario creation, two kinds of scenario files are used. The first is a movement pattern file that describes the movement that all nodes should undergo during the simulation. The second is a communication pattern file that describes the packet workload that is offered to the network layer during the simulation. To get the performance of MSR under different moving speeds environment, we use two simulation sets with speed 1 m/s and 2Om/s respectively. Our simulations model a network of 50 mobile hosts placed randomly within a 1500mx300m area, both with zero pause time. To evaluate the performance of MSR, we experimented with different application traffic, including CBR and FTP. CBR uses UDP as its transport protocol, and FTP uses TCP. The channel is assumed error-free except for the presence of collision. For other simulation detail, please refer [2] 6.2 Performance Metrics In performance evaluation, we choose the following metrics: Queue size: The queue size of an IFQ object at each node; Packet delivery ratio: The ratio between the number of packets originated by the application layer CBR sources and the number of packets received by the CBR sink at the final destination; Data throughput: The total number of packets received during a measuring interval divided by the measurement interval; End-to-end delay; Packet drop probability. For TCP, another issue concerned is the out-of-order problem. To present the packet dynamics clearly, the ack time-sequence plot is given. 6.3 Simulation Results 6.3.1 UDP traffic (max moving speed of 20 m/s) We first look at CBR traffic implemented with UDP agents. A scenario with 20 CBR connections is adopted. Since UDP has no feedback control mechanism, all the CBR traffic generated is constant no matter how the network runs. So it can act as a good test bed for comparing routing protocols. We shall use it as a reference point. Fig. 1 shows that fewer CBR packets are dropped in MSR than that in DSR. Table I shows drop summery in detail; the main reason of dropping is No Route and IFQ Full. Fig. 2 Page 23 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 23 provides the end-to-end packet delivery ratio of every connection, and the comparison shows MSR is better than DSR. Page 24 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 24Page 25 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 25 From Fig. 3 we can see that MSR achieves higher throughput than DSR almost on every connection, just as we expected. This can be attributed to the fact that the multipath routing effectively utilizes currently unallocated network resources. Fig. 4 shows the end-to-end delay of every connection. Fig. 5 presents the average queue size for all 50 hosts. From Fig. 5, we can see that, in MSR, the packets that should have been queued in the IFQ have been redistributed to other nodes that have light load, through which the traffic is balanced. Balancing the route load in MSR shortens the delay as the chance of congestion is reduced. Table 11 shows the routing overheads in DSR and MSR respectively. We can see the routing messages in DSR are only little more than that of DSR. However, the packet drops probability is lower than that of DSR. The main drop reason is still No Route and IFQ Full. Page 26 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 26 6.3.2 TCP traffic (max- moving speed 20m/s) For TCP traffic, we take a scenario with 30 FTP connections, with network rather heavily loaded. Since TCP has an AIMD (Additive increase Multiplicative Decrease) feedback control mechanism, the statistics at every node has less meaning than that of UDP, we focus on the end-to-end packet dynamics instead. Figs. 6 and 7 show that the multipath routing can also be used to reduce the end-to-end network latency and message drop probability, or increase the likelihood of message delivery for TCP connections. From Figs. 8 and 9, we can see there are not many out-of order deliveries in MSR. On the contrary, the end-to-end throughput of TCP in MSR has increased a lot due to the smooth increase of sequence number. Fig. 9 also implies that MSR recovers more quickly than DSR does when the connection meets severe packets droppings (e.g. at time 90s). It illustrates that cur load-balancing method achieves a good switching granularity.Page 27 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 27 CHAPTER 7 DISCUSSIONS In our initial experiments, we found that the major statistics of Routing Packets of MSR is comparable to that of DSR, except that the GRAT packets count in MSR is too large compared to DSR. Thus we turn off the gratuitous options, and the results become better. The simulation results show that the main reason for packet drops in DSR is No Route and IFQ Full, while these two factors improve a lot in MSR. Under max speed Id s , the throughput and end-to-end delay of MSR are also better than those of DSR. There is no significant difference of packet drops between DSR and MSR. Therefore, we can conclude that one of the mail gains we get from MSR is attributed to less No Route drops. In other words, multipath routing compensates for route failures efficiently in high-speed movement. It is consistent with the results in Tables I and 11. When evaluating a network routing protocol, control load should also be considered. There is no more control load in MSR than that in DSR, except for probing packets transmitted in networks. Since we use SRping (which is unicast), rather than flooding, to test the validity of paths currently used, and the probing interval we choose is very conservative, there is little overload added. Page 28 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 28 Fig 8. TCP segments time-sequence plot of a heavy connection Node 49 to node 50 Page 29 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 29Page 30 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 30 CHAPTER 8 CONCLUSIONS In this paper, a new multipath routing protocol in ad hoc networks, MSR is presented. Our protocol is a direct descendant of DSR. By incorporating the multipath mechanism into DSR and employing a probing based load-balancing mechanism, the throughput, end-to-end delay, and drop probability have been improved significantly. The drawback of MSR may be the processing overhead of originating the packets. Fortunately the computer is becoming more powerful and cheaper. So it may not be the obstacle to the deployment of MSR.. Page 31 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 31 APPENDIX LIST OF FIGURES Page No. Fig 1.1 - Adhoc networks 8 Fig.2.1 Infrastructure network 11 Fig.2.2 Rapidly Deployable Network 12 Fig 5.1 Route discovery in MSR 15 Fig 5.2 Route Discovery in MSR(contd) 16 Fig 5.3 Route Discovery in MSR(contd) 17 Fig 5.4 Route Reply in MSR 18 Fig 5.5 Data delivery in MSR 18 Fig .1 CBR packets dropped at each node 23 Fig .2 Packet delivery ratio of every connection 24 Fig .3 End to-end throughput 24 Fig .4 End to end delay 25 Fig .5 IFQ queue size at each node 25 Fig .6 End to throughput of each connection 27 Fig .7 End to delay of each connection 28 Fig 8. TCP segments time-sequence plot of a heavy connection 28 Node 49 to node 50 Fig .9 Time sequence plot with sequence # mod 300 29 Page 32 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 32 LIST OF TABLES Page no Table I 23 Table II 26Page 33 Adaptive Routing in Adhoc Networks Department of computer Science CUSAT 33 REFERENCES 1. Adaptive Multipath Source Routing in Ad Hoc Networks. Lei Wang, Yantai Shu,Miao Dong, and. Lianfang Zhang. Department of Computer Science .. ieexplore.ieeiel5/7452/20263/00937362.pdf? 2. Implementing multipath source routing in a wireless ad hoc network ..evaluation of multipath source routing was conducted and. compared with dynamic source routing .. (Multipath Source Routing) [7] is one such protocol our .. ieexplore.ieeiel5/10170/32495/01517283.pdf? 3. Welcome to IEE Xplore 2.0: Adaptive multipath source routing in ..Adaptive multipath source routing in ad hoc networks Lei Wang Yantai Shu Miao Dong Lianfang Zhang Yang, O.W.W. Dept. of Comput. Sci., Tianjin Univ.; .. ieexplore.ieexpls/abs_all.jsp? 4. http://ietfproceedings/97dec/97dec-final-93.htm Adaptive Multipath Source Routing in Ad Hoc Networks 5. ieexplore.ieeiel5/8375/26364/01173115.pdf?arnumber=1173115 6. J. Broch, D. B. Johnson, and D. A. Maltz. The dynamic source routing protocol for mobile ad hoc networks. http://ietf.org /internetdrafts/draft-ietf- manet-dsr-03.txJtu, ne 1999. 7. J. Broch, D. A. Maltz, D. B. Johnson, Y-C. Hu, and J. Jetcheva. A performance comparison of multi-hop wireless ad hoc network routing protocols. In ACM MOBICOM 98, pp. 85-97, October 1998. 8. D. B. Johnson and D. A. Maltz, Dynamic Source Routing in AdHoc Wireless Networks, In Mobile Computing, edited by Tomasz Imielinski and Hank Korth, Chapter 5, Kluwer Academic Publishers, 1996,pp. 153-181. 9. MANET. http://ietfhtml.charters/manet-charter.html. 10. AdHoc wireless Networks Architectures and Protocols By C. Siva Ram Murthy and B.S. Manoj 11. ns, http://mash.cs.berkeley.edu/ns. 12. L. Wang, L. F. Zhang, Y. T. Shu, M. Dong, and 0. W. W. Yang, Multipath Source Routing in Wireless Ad Hoc Networks, in Proceedings of the IEE CCECE, pp. 479-483, Halifax, Nova Scotia, Canada, May 7-10.2000 SEMINAR REPORT on Adaptive Routing in Adhoc Networks - Dharanitharan.B - 08-17-2017 [attachment=653] ABSTRACT The dynamics of an ad hoc network are a challenge to protocol design because mobility inevitably leads to unstable routing, and consequently flows encounter fluctuations in resource availability on various paths during the lifetime of a session. This has become serious, especially for those protocols based on single-path reservation, as frequent reservation and restoration of reservation-based flows increase the instability of connections. Advances in wireless research are focusing more and more on the adaptation capability of routing protocols due to the interrelationship among various performance measures such as those related to topological changes (link breakages, node mobility, etc.) and quality of service (QoS) parameters (load, delay, etc). After giving a more detailed discussion of the existing work in adaptive routing, we propose a new routing protocol for adhoc wireless networks - Multipath Source Routing (MSR), which is an extension of DSR(Dynamic Source Routing) that incorporates the multipath mechanism into DSR. Based on the measurement of RTT(Round Trip Time), we propose a scheme to distribute load among multiple paths. MSR is an adaptive routing for ad hoc networks. It considers the two fundamental issues in its design. MSR may adapt to topology changes by retaining the route discovery and route maintenance mechanism of DSR. In addition, MSR employs a probing-based load-balancing mechanism. Simulation results show that MSR can improve the packet delivery ratio and the throughput of TCP and UDP, and it reduces the end-to-end delay and the average queue size while adding little overhead. As a result, MSR decreases network congestion and increases the path fault tolerance quite well. SEMINAR REPORT on Adaptive Routing in Adhoc Networks - SREE - 08-17-2017 to get information about the topic "adaptive opportunistic routing for wireless ad hoc networks" full report ppt and related topic refer the page link bellow http://seminarsprojects.net/Thread-car-context-aware-adaptive-routing-for-delay-tolerant-mobile-networks?pid=46733&mode=threaded http://seminarsprojects.net/Thread-seminar-report-on-adaptive-routing-in-adhoc-networks?pid=2894&mode=threaded |