The document discusses two on-demand routing protocols for ad-hoc networks: AODV and DSR. It provides an overview of ad-hoc networks and routing algorithms. It then describes the key mechanisms and operations of AODV, including path discovery using route requests, path maintenance through link failure detection, and local connectivity maintenance with hello messages. It also outlines the general approach and basic route discovery and maintenance processes used in DSR.
This document discusses MANET routing protocols and compares AODV and DSR protocols. It provides an overview of ad hoc networks and their key characteristics like being decentralized and relying on participating nodes to forward data. It then describes the main categories of ad hoc routing protocols - proactive (table-driven) and reactive (on-demand). The document dives deeper into AODV and DSR protocols, explaining their path discovery, maintenance and other mechanisms. The key differences noted are that DSR can handle uni-directional and bi-directional links while both protocols employ on-demand routing and broadcast discovery but use different approaches for route information storage and link failure handling.
Routing Protocols for Ad-Hoc Networks. This is a book for Ad-hoc On-Demand Distance Vector Routing
&
DSR: The Dynamic Source Routing Protocol for Multi-Hop Wireless Ad Hoc Networks. November 2011,
Authors : Giorgos Papadakis & Manolis Surligas
PERFORMANCE ANALYSIS AND COMPARISON OF IMPROVED DSR WITH DSR, AODV AND DSDV R...ijp2p
Mobile Ad-hoc networks are categorized by multi-hop wireless connectivity and numbers of nodes are connecting each other through wireless network. It includes several routing protocols specifically designed for ad-hoc routing. The most widely used ad hoc routing protocols are Ad-hoc On Demand Distance Vector (AODV), Destination Sequence Distance Vector (DSDV), and Dynamic Source Routing (DSR). In this paper, we present an analysis of DSR protocol and propose our algorithm to improve the performance of DSR protocol by using small delay applied on last route ACK path when an original route fails in Mobile Ad Hoc networks. Past researchers the MANET have focused on simulation study by varying network parameters, such as network size, number of nodes. The simulation results shows that the M-DSR protocol
having some excellent performance Metrics then other protocols. We have taken different performance parameters over the comparison of Modified -DSR with other three protocols in mobility as well as Nonmobility scenario up to 300 nodes in MANETs using NS2 simulator. To achieve this goal DSR is modified by using modified algorithm technique in order to load balancing, to avoid congestion and lower packet
delivery.
Our area of interest for the paper is the improvement of performance of DSR routing protocol by
changing in algorithm and this Improved DSR protocol should compare with remaining protocols
taken in this research paper.
2. In this paper we made changesin traditional DSR protocol and generation of new improved DSR the
different performance parameters and compare with AODV/DSR/DSDV protocols in mobility and
non- mobility scenarios nodes up to 300.
3. We can plot the graphs throughput, End to end Delay, Packet delivery Ratio, Dropping Ratio, and
average energy consumption on Mobility and Non-Mobility scenario by using Network Simulator
version 2.34 for Modified DSR protocols. M-DSR, DSDV perform well when Mobility is low.
DSDV is a proactive routing protocol that uses destination sequence numbers to ensure loop-free routing in mobile ad hoc networks. Each node maintains a routing table with destination addresses, next hops, metrics, and sequence numbers. Nodes periodically broadcast their full routing tables, and also broadcast updates immediately after changes to avoid loops and converge quickly. DSDV addresses issues with traditional distance vector routing through the use of sequence numbers and by damping route fluctuations.
The document compares the AODV and OLSR routing protocols for mobile ad hoc networks. AODV is a reactive protocol that establishes routes on demand, while OLSR is a proactive protocol that maintains routes to all nodes. OLSR generally has lower latency than AODV but higher overhead. Both protocols elect multipoint relays to reduce flooding. AODV uses less bandwidth but requires route discovery, while OLSR maintains all routes continuously.
DSDV is a proactive routing protocol that extends distance-vector routing for mobile ad hoc networks. It adds sequence numbers to routing table updates to prevent routing loops, and uses damping to hold updates for short-lived changes. Each node periodically broadcasts its full routing table or incremental updates to neighbors. When multiple routes to a destination are received, the route with the highest sequence number is chosen.
Simulation & comparison of aodv & dsr protocolPrafull Johri
This document summarizes and compares two reactive routing protocols - AODV and DSR. It discusses how NS2 was extended to simulate wireless networks and the two protocols. AODV uses route discovery to find paths, maintains route tables, and can locally repair broken links. DSR also uses route discovery but source routes are carried in packet headers. While AODV has lower initial packet loss, DSR performance improves over time, so either protocol can be used for longer simulations.
The document summarizes several routing protocols used in wireless networks. It discusses both table-driven protocols like DSDV and on-demand protocols like AODV. It provides details on how each protocol performs routing and maintains routes. It also outlines some advantages and disadvantages of protocols like DSDV, AODV, DSR, and TORA.
This document discusses MANET routing protocols and compares AODV and DSR protocols. It provides an overview of ad hoc networks and their key characteristics like being decentralized and relying on participating nodes to forward data. It then describes the main categories of ad hoc routing protocols - proactive (table-driven) and reactive (on-demand). The document dives deeper into AODV and DSR protocols, explaining their path discovery, maintenance and other mechanisms. The key differences noted are that DSR can handle uni-directional and bi-directional links while both protocols employ on-demand routing and broadcast discovery but use different approaches for route information storage and link failure handling.
Routing Protocols for Ad-Hoc Networks. This is a book for Ad-hoc On-Demand Distance Vector Routing
&
DSR: The Dynamic Source Routing Protocol for Multi-Hop Wireless Ad Hoc Networks. November 2011,
Authors : Giorgos Papadakis & Manolis Surligas
PERFORMANCE ANALYSIS AND COMPARISON OF IMPROVED DSR WITH DSR, AODV AND DSDV R...ijp2p
Mobile Ad-hoc networks are categorized by multi-hop wireless connectivity and numbers of nodes are connecting each other through wireless network. It includes several routing protocols specifically designed for ad-hoc routing. The most widely used ad hoc routing protocols are Ad-hoc On Demand Distance Vector (AODV), Destination Sequence Distance Vector (DSDV), and Dynamic Source Routing (DSR). In this paper, we present an analysis of DSR protocol and propose our algorithm to improve the performance of DSR protocol by using small delay applied on last route ACK path when an original route fails in Mobile Ad Hoc networks. Past researchers the MANET have focused on simulation study by varying network parameters, such as network size, number of nodes. The simulation results shows that the M-DSR protocol
having some excellent performance Metrics then other protocols. We have taken different performance parameters over the comparison of Modified -DSR with other three protocols in mobility as well as Nonmobility scenario up to 300 nodes in MANETs using NS2 simulator. To achieve this goal DSR is modified by using modified algorithm technique in order to load balancing, to avoid congestion and lower packet
delivery.
Our area of interest for the paper is the improvement of performance of DSR routing protocol by
changing in algorithm and this Improved DSR protocol should compare with remaining protocols
taken in this research paper.
2. In this paper we made changesin traditional DSR protocol and generation of new improved DSR the
different performance parameters and compare with AODV/DSR/DSDV protocols in mobility and
non- mobility scenarios nodes up to 300.
3. We can plot the graphs throughput, End to end Delay, Packet delivery Ratio, Dropping Ratio, and
average energy consumption on Mobility and Non-Mobility scenario by using Network Simulator
version 2.34 for Modified DSR protocols. M-DSR, DSDV perform well when Mobility is low.
DSDV is a proactive routing protocol that uses destination sequence numbers to ensure loop-free routing in mobile ad hoc networks. Each node maintains a routing table with destination addresses, next hops, metrics, and sequence numbers. Nodes periodically broadcast their full routing tables, and also broadcast updates immediately after changes to avoid loops and converge quickly. DSDV addresses issues with traditional distance vector routing through the use of sequence numbers and by damping route fluctuations.
The document compares the AODV and OLSR routing protocols for mobile ad hoc networks. AODV is a reactive protocol that establishes routes on demand, while OLSR is a proactive protocol that maintains routes to all nodes. OLSR generally has lower latency than AODV but higher overhead. Both protocols elect multipoint relays to reduce flooding. AODV uses less bandwidth but requires route discovery, while OLSR maintains all routes continuously.
DSDV is a proactive routing protocol that extends distance-vector routing for mobile ad hoc networks. It adds sequence numbers to routing table updates to prevent routing loops, and uses damping to hold updates for short-lived changes. Each node periodically broadcasts its full routing table or incremental updates to neighbors. When multiple routes to a destination are received, the route with the highest sequence number is chosen.
Simulation & comparison of aodv & dsr protocolPrafull Johri
This document summarizes and compares two reactive routing protocols - AODV and DSR. It discusses how NS2 was extended to simulate wireless networks and the two protocols. AODV uses route discovery to find paths, maintains route tables, and can locally repair broken links. DSR also uses route discovery but source routes are carried in packet headers. While AODV has lower initial packet loss, DSR performance improves over time, so either protocol can be used for longer simulations.
The document summarizes several routing protocols used in wireless networks. It discusses both table-driven protocols like DSDV and on-demand protocols like AODV. It provides details on how each protocol performs routing and maintains routes. It also outlines some advantages and disadvantages of protocols like DSDV, AODV, DSR, and TORA.
Performance Evaluation of Routing Protocols Ankush Mehta
This is a research project based on Performance checking of the Routing Protocols. This Presentation shows the basic knowledge of the Protocols use (AODV, DSDV and DSR) and in the end it shows the Result and Conclusion by comparing the graphs which are generated through out the work.
Research Inventy : International Journal of Engineering and Scienceresearchinventy
The document summarizes a study that evaluated the performance of three mobile ad hoc network (MANET) routing protocols: AODV, DSDV, and DSR. The protocols were simulated using the NS-2 network simulator across networks of 30 to 70 nodes. Key performance metrics analyzed include packet delivery fraction, average end-to-end delay, normalized routing load, and packet loss. The results found that AODV performed best in terms of packet delivery fraction and shortest end-to-end delay, while DSDV had the lowest normalized routing load and DSR had the lowest packet loss. Overall, the document compares the performance of these three MANET routing protocols under different conditions using simulation results.
DSDV is a proactive routing protocol that uses periodic routing table exchanges and sequence numbers to avoid loops. AODV is a reactive protocol based on DSDV that uses on-demand route discovery with broadcast RREQ and unicast RREP messages to find routes, and maintains routing tables at nodes instead of in packet headers like DSR. Both protocols aim to quickly adapt to dynamic links with low overhead.
AODV is a reactive routing protocol for mobile ad hoc networks. It uses route discovery and maintenance to dynamically discover and maintain routes. Route discovery uses route request (RREQ) and route reply (RREP) messages to find routes between nodes. Route maintenance uses route error (RERR) messages to notify nodes of link breaks. Each node maintains a routing table with next hop and destination information.
The document discusses various network layer services and routing algorithms. It describes packet switching which allows packets to be forwarded using destination addresses and connection-oriented services which require call setup and use virtual circuit identifiers. It also summarizes different routing algorithms including flooding, distance vector, link state, hierarchical routing, multicast routing, and routing for mobile and ad hoc networks.
This document provides a literature review of research papers on detecting and preventing blackhole attacks in the AODV routing protocol for mobile ad hoc networks (MANETs). It summarizes 9 papers that propose various techniques like using sequence numbers, watchdog mechanisms, and route confirmation messages to identify malicious nodes and increase security. The document outlines the key ideas, results, and potential future work from each paper to improve performance and security against blackhole attacks in AODV routing.
Performance Analysis and Simulation of OLSR Routing Protocol in MANET ijcnac
Mobile ad hoc network is a collection of wireless nodes that are communicate other
nodes (router) without using access point, infrastructure . Mobile ad-hoc network is an
autonomous system that means no need for depaentd other nodes it have own capability
to handle and controlling all funcitionlity, to sending and receiving all information form
one device to other device. MANET has power full feature that controlling itself by
dynamic nature, multihop,low power and configuration of the system. In this paper we
analyzing, simulation and implements the TC messages and HELLO Message by MPR of
OLSR routing performance checked at 200 nodes on Qualnet 5.0.2 simulator. In Qualnet
simulator to simulate and implement the performance of OLSR routing protocols takes
various performance metrics like hello message sent (HMS) , hello message received
(HMR), TC message generated (TCMG), TC message replied (TCMR), TC messages
received on Constant Bit Rate (CBR) using random waypoint model. In this paper check
the performance OLSR routing protocol gives effective performance for lage networks.
The document provides an overview of concepts related to the data link layer. It discusses functions of the data link layer including framing, flow control, and error detection. It also covers topics such as HDLC, PPP, channel allocation problems, multiple access protocols including ALOHA, CSMA, CSMA/CD, and channelization techniques like FDMA, TDMA, and CDMA. Specific standards for wired LANs like Ethernet and wireless LANs like IEEE 802.11 are also mentioned. Finally, it briefly discusses technologies like token bus, token ring, and virtual LANs.
Dynamic Source Routing uses route discovery to find routes between nodes. When a node receives a route request (RREQ) message, if it is the destination it returns a route reply (RREP) with the accumulated route record to the sender. If it is an intermediate node, it discards the RREQ if it has the same ID or finds its own address in the route, otherwise it appends its address to the route record and propagates the RREQ to neighbors to continue finding a path to the destination.
This document provides an overview of key concepts in network layer delivery, forwarding, and routing. It discusses delivery and forwarding of packets, including direct vs indirect delivery and next-hop vs route forwarding methods. It also summarizes several unicast routing protocols, including distance vector protocols like RIP and link state protocols like OSPF. Finally, it discusses path vector routing and Border Gateway Protocol (BGP) for interdomain routing.
This document provides an overview of different routing protocols. It discusses IP routing, static routing, and dynamic routing. It also covers proactive routing protocols like DSDV which maintain routing tables and periodically update them. Reactive protocols like DSR and AODV establish routes on demand. Hybrid protocols combine proactive and reactive approaches. The document describes the key processes, advantages, and disadvantages of DSDV, DSR, AODV, and zone routing protocol.
This document discusses routing protocols for mobile ad-hoc networks (MANETs). It introduces several routing protocols including proactive (table-driven) protocols like Destination-Sequenced Distance Vector (DSDV), reactive (on-demand) protocols like Ad-hoc On-Demand Distance Vector (AODV) and Dynamic Source Routing (DSR), and hybrid protocols like Zone Routing Protocol (ZRP) that use both proactive and reactive approaches. For each protocol, it provides a brief overview of the routing approach and algorithm. It also compares the characteristics of proactive, reactive and hybrid routing protocols.
Routing is the mechanism for finding the most cost-effective path from source to destination in a packet switching network. There are several desirable properties for routing algorithms including correctness, robustness, stability, fairness, and efficiency. Common routing strategies include fixed/static routing, flooding, random routing, flow-based routing, and adaptive/dynamic routing. Fixed routing selects predetermined routes that may only change if the network topology changes, while flooding explores all possible routes by sending every incoming packet out every outgoing line except the one it arrived on.
1) The document describes the Ad Hoc On-Demand Distance Vector (AODV) routing protocol. AODV is a reactive protocol that discovers routes on-demand using a route discovery process.
2) When a node needs to send a packet to an unknown destination, it broadcasts a route request (RREQ) to its neighbors. Neighbors set up reverse paths and rebroadcast the RREQ until it reaches the destination node.
3) The destination or intermediate nodes with a route can send a unicast route reply (RREP) back to the source node using the reverse path. This sets up a forward path from source to destination for data packets.
Routing is the process of moving information across an internetwork from a source to a destination. There are two types of routing: direct delivery where the source and destination are on the same network, and indirect delivery where packets travel through multiple routers to reach the destination on a different network. Distance vector routing protocols like RIP use hop count as the metric and periodically share routing tables with neighboring routers to allow all routers to learn the optimal paths. However, this can cause instability issues like two-node and three-node loops where routers incorrectly update their routing tables.
Routing is the operation of transferring information transversely through an internetwork from a source to a destination. Alongside the approach, as a minimum one middle node normally is found. Routing is frequently compared with bridging, Copy the link given below and paste it in new browser window to get more information on Network Routing:- http://www.transtutors.com/homework-help/computer-science/network-routing.aspx
The network layer is responsible for routing packets from the source to destination. The routing algorithm is the piece of software that decides where a packet goes next (e.g., which output line, or which node on a broadcast channel).For connectionless networks, the routing decision is made for each datagram. For connection-oriented networks, the decision is made once, at circuit setup time.
Routing Issues
The routing algorithm must deal with the following issues:
Correctness and simplicity: networks are never taken down; individual parts (e.g., links, routers) may fail, but the whole network should not.
Stability: if a link or router fails, how much time elapses before the remaining routers recognize the topology change? (Some never do..)
Fairness and optimality: an inherently intractable problem. Definition of optimality usually doesn't consider fairness. Do we want to maximize channel usage? Minimize average delay?
When we look at routing in detail, we'll consider both adaptive--those that take current traffic and topology into consideration--and nonadaptive algorithms.
AODV (Ad hoc On-demand Distance Vector) VS AOMDV (Ad hoc On-demand Multipath ...Ann Joseph
The document discusses Ad hoc On-demand Multipath Distance Vector (AOMDV), which is a multipath extension of the AODV routing protocol for mobile ad hoc networks. AOMDV discovers multiple loop-free and disjoint paths between source and destination nodes in a single route discovery to improve fault tolerance. It provides benefits like lower end-to-end delay, higher throughput, and reduced route discovery operations compared to AODV, which is a single path routing protocol.
- Mobile ad hoc networks (MANETs) are autonomous systems of wireless nodes that can dynamically change topology as nodes move. Routing must adapt to these changes.
- There are two main categories of routing protocols: table-driven protocols proactively maintain consistent, up-to-date routing tables whereas on-demand protocols only determine routes when needed.
- Examples of protocols include DSDV as a table-driven protocol and AODV as an on-demand protocol, with AODV using route requests and replies to discover routes only when transmitting data.
The Effects of Speed on the Performance of Routing Protocols in Mobile Ad-hoc...Narendra Singh Yadav
Mobile ad hoc network is a collection of mobile nodes communicating through wireless channels without any existing network infrastructure or centralized administration. Because of the limited transmission range of wireless network interfaces, multiple "hops" may be needed to exchange data across the network. Consequently, many routing algorithms have come into existence to satisfy the needs of communications in such networks. Researchers have conducted many simulations comparing the performance of these routing protocols under various conditions and constraints. One question that arises is whether speed of nodes affects the relative performance of routing protocols being studied. This paper addresses the question by simulating two routing protocols AODV and DSDV. Protocols were simulated using the ns-2 and were compared in terms of packet delivery fraction, normalized routing load and average delay, while varying number of nodes, and speed.
Performance Evaluation of Routing Protocols Ankush Mehta
This is a research project based on Performance checking of the Routing Protocols. This Presentation shows the basic knowledge of the Protocols use (AODV, DSDV and DSR) and in the end it shows the Result and Conclusion by comparing the graphs which are generated through out the work.
Research Inventy : International Journal of Engineering and Scienceresearchinventy
The document summarizes a study that evaluated the performance of three mobile ad hoc network (MANET) routing protocols: AODV, DSDV, and DSR. The protocols were simulated using the NS-2 network simulator across networks of 30 to 70 nodes. Key performance metrics analyzed include packet delivery fraction, average end-to-end delay, normalized routing load, and packet loss. The results found that AODV performed best in terms of packet delivery fraction and shortest end-to-end delay, while DSDV had the lowest normalized routing load and DSR had the lowest packet loss. Overall, the document compares the performance of these three MANET routing protocols under different conditions using simulation results.
DSDV is a proactive routing protocol that uses periodic routing table exchanges and sequence numbers to avoid loops. AODV is a reactive protocol based on DSDV that uses on-demand route discovery with broadcast RREQ and unicast RREP messages to find routes, and maintains routing tables at nodes instead of in packet headers like DSR. Both protocols aim to quickly adapt to dynamic links with low overhead.
AODV is a reactive routing protocol for mobile ad hoc networks. It uses route discovery and maintenance to dynamically discover and maintain routes. Route discovery uses route request (RREQ) and route reply (RREP) messages to find routes between nodes. Route maintenance uses route error (RERR) messages to notify nodes of link breaks. Each node maintains a routing table with next hop and destination information.
The document discusses various network layer services and routing algorithms. It describes packet switching which allows packets to be forwarded using destination addresses and connection-oriented services which require call setup and use virtual circuit identifiers. It also summarizes different routing algorithms including flooding, distance vector, link state, hierarchical routing, multicast routing, and routing for mobile and ad hoc networks.
This document provides a literature review of research papers on detecting and preventing blackhole attacks in the AODV routing protocol for mobile ad hoc networks (MANETs). It summarizes 9 papers that propose various techniques like using sequence numbers, watchdog mechanisms, and route confirmation messages to identify malicious nodes and increase security. The document outlines the key ideas, results, and potential future work from each paper to improve performance and security against blackhole attacks in AODV routing.
Performance Analysis and Simulation of OLSR Routing Protocol in MANET ijcnac
Mobile ad hoc network is a collection of wireless nodes that are communicate other
nodes (router) without using access point, infrastructure . Mobile ad-hoc network is an
autonomous system that means no need for depaentd other nodes it have own capability
to handle and controlling all funcitionlity, to sending and receiving all information form
one device to other device. MANET has power full feature that controlling itself by
dynamic nature, multihop,low power and configuration of the system. In this paper we
analyzing, simulation and implements the TC messages and HELLO Message by MPR of
OLSR routing performance checked at 200 nodes on Qualnet 5.0.2 simulator. In Qualnet
simulator to simulate and implement the performance of OLSR routing protocols takes
various performance metrics like hello message sent (HMS) , hello message received
(HMR), TC message generated (TCMG), TC message replied (TCMR), TC messages
received on Constant Bit Rate (CBR) using random waypoint model. In this paper check
the performance OLSR routing protocol gives effective performance for lage networks.
The document provides an overview of concepts related to the data link layer. It discusses functions of the data link layer including framing, flow control, and error detection. It also covers topics such as HDLC, PPP, channel allocation problems, multiple access protocols including ALOHA, CSMA, CSMA/CD, and channelization techniques like FDMA, TDMA, and CDMA. Specific standards for wired LANs like Ethernet and wireless LANs like IEEE 802.11 are also mentioned. Finally, it briefly discusses technologies like token bus, token ring, and virtual LANs.
Dynamic Source Routing uses route discovery to find routes between nodes. When a node receives a route request (RREQ) message, if it is the destination it returns a route reply (RREP) with the accumulated route record to the sender. If it is an intermediate node, it discards the RREQ if it has the same ID or finds its own address in the route, otherwise it appends its address to the route record and propagates the RREQ to neighbors to continue finding a path to the destination.
This document provides an overview of key concepts in network layer delivery, forwarding, and routing. It discusses delivery and forwarding of packets, including direct vs indirect delivery and next-hop vs route forwarding methods. It also summarizes several unicast routing protocols, including distance vector protocols like RIP and link state protocols like OSPF. Finally, it discusses path vector routing and Border Gateway Protocol (BGP) for interdomain routing.
This document provides an overview of different routing protocols. It discusses IP routing, static routing, and dynamic routing. It also covers proactive routing protocols like DSDV which maintain routing tables and periodically update them. Reactive protocols like DSR and AODV establish routes on demand. Hybrid protocols combine proactive and reactive approaches. The document describes the key processes, advantages, and disadvantages of DSDV, DSR, AODV, and zone routing protocol.
This document discusses routing protocols for mobile ad-hoc networks (MANETs). It introduces several routing protocols including proactive (table-driven) protocols like Destination-Sequenced Distance Vector (DSDV), reactive (on-demand) protocols like Ad-hoc On-Demand Distance Vector (AODV) and Dynamic Source Routing (DSR), and hybrid protocols like Zone Routing Protocol (ZRP) that use both proactive and reactive approaches. For each protocol, it provides a brief overview of the routing approach and algorithm. It also compares the characteristics of proactive, reactive and hybrid routing protocols.
Routing is the mechanism for finding the most cost-effective path from source to destination in a packet switching network. There are several desirable properties for routing algorithms including correctness, robustness, stability, fairness, and efficiency. Common routing strategies include fixed/static routing, flooding, random routing, flow-based routing, and adaptive/dynamic routing. Fixed routing selects predetermined routes that may only change if the network topology changes, while flooding explores all possible routes by sending every incoming packet out every outgoing line except the one it arrived on.
1) The document describes the Ad Hoc On-Demand Distance Vector (AODV) routing protocol. AODV is a reactive protocol that discovers routes on-demand using a route discovery process.
2) When a node needs to send a packet to an unknown destination, it broadcasts a route request (RREQ) to its neighbors. Neighbors set up reverse paths and rebroadcast the RREQ until it reaches the destination node.
3) The destination or intermediate nodes with a route can send a unicast route reply (RREP) back to the source node using the reverse path. This sets up a forward path from source to destination for data packets.
Routing is the process of moving information across an internetwork from a source to a destination. There are two types of routing: direct delivery where the source and destination are on the same network, and indirect delivery where packets travel through multiple routers to reach the destination on a different network. Distance vector routing protocols like RIP use hop count as the metric and periodically share routing tables with neighboring routers to allow all routers to learn the optimal paths. However, this can cause instability issues like two-node and three-node loops where routers incorrectly update their routing tables.
Routing is the operation of transferring information transversely through an internetwork from a source to a destination. Alongside the approach, as a minimum one middle node normally is found. Routing is frequently compared with bridging, Copy the link given below and paste it in new browser window to get more information on Network Routing:- http://www.transtutors.com/homework-help/computer-science/network-routing.aspx
The network layer is responsible for routing packets from the source to destination. The routing algorithm is the piece of software that decides where a packet goes next (e.g., which output line, or which node on a broadcast channel).For connectionless networks, the routing decision is made for each datagram. For connection-oriented networks, the decision is made once, at circuit setup time.
Routing Issues
The routing algorithm must deal with the following issues:
Correctness and simplicity: networks are never taken down; individual parts (e.g., links, routers) may fail, but the whole network should not.
Stability: if a link or router fails, how much time elapses before the remaining routers recognize the topology change? (Some never do..)
Fairness and optimality: an inherently intractable problem. Definition of optimality usually doesn't consider fairness. Do we want to maximize channel usage? Minimize average delay?
When we look at routing in detail, we'll consider both adaptive--those that take current traffic and topology into consideration--and nonadaptive algorithms.
AODV (Ad hoc On-demand Distance Vector) VS AOMDV (Ad hoc On-demand Multipath ...Ann Joseph
The document discusses Ad hoc On-demand Multipath Distance Vector (AOMDV), which is a multipath extension of the AODV routing protocol for mobile ad hoc networks. AOMDV discovers multiple loop-free and disjoint paths between source and destination nodes in a single route discovery to improve fault tolerance. It provides benefits like lower end-to-end delay, higher throughput, and reduced route discovery operations compared to AODV, which is a single path routing protocol.
- Mobile ad hoc networks (MANETs) are autonomous systems of wireless nodes that can dynamically change topology as nodes move. Routing must adapt to these changes.
- There are two main categories of routing protocols: table-driven protocols proactively maintain consistent, up-to-date routing tables whereas on-demand protocols only determine routes when needed.
- Examples of protocols include DSDV as a table-driven protocol and AODV as an on-demand protocol, with AODV using route requests and replies to discover routes only when transmitting data.
The Effects of Speed on the Performance of Routing Protocols in Mobile Ad-hoc...Narendra Singh Yadav
Mobile ad hoc network is a collection of mobile nodes communicating through wireless channels without any existing network infrastructure or centralized administration. Because of the limited transmission range of wireless network interfaces, multiple "hops" may be needed to exchange data across the network. Consequently, many routing algorithms have come into existence to satisfy the needs of communications in such networks. Researchers have conducted many simulations comparing the performance of these routing protocols under various conditions and constraints. One question that arises is whether speed of nodes affects the relative performance of routing protocols being studied. This paper addresses the question by simulating two routing protocols AODV and DSDV. Protocols were simulated using the ns-2 and were compared in terms of packet delivery fraction, normalized routing load and average delay, while varying number of nodes, and speed.
Analyzing the Effect of Varying CBR on AODV, DSR, IERP Routing Protocols in M...IOSR Journals
This document analyzes the performance of the AODV, DSR, and IERP routing protocols in a mobile ad hoc network (MANET) with varying constant bit rate (CBR) traffic loads. It conducts simulations in QualNet 6.1 and evaluates the protocols based on average end-to-end delay, throughput, average jitter, and packet delivery ratio under different CBR values. The results show that AODV generally performs best with low and stable delay, jitter and high throughput and delivery ratio. DSR has better performance than IERP for throughput and delivery ratio. IERP shows the worst performance for delay and jitter as CBR increases. The document concludes by stating AODV is best overall but
Survey of Modified Routing Protocols for Mobile Ad-hoc Networkijsrd.com
In last few years extensive research work has been done in the field of routing protocols for Ad-hoc Network. Various routing protocols have been evaluated in different network conditions using different performance metrics. A lot of research has been done how to modify standard routing protocol in ad-hoc network to improve its performance. The hop count is not only metric that gives efficient routing path. There are various modified protocols which make the use of other parameters along with hop count to select the best routing path to the destination. In standard Ad-hoc On-demand Distance Vector (AODV) routing protocol only hop count is used for selecting the routing path. In this paper we have studied variants of AODV protocols with modified routing metric.
This document provides an overview of the Dynamic Source Routing (DSR) protocol for mobile ad hoc networks. DSR is a reactive, on-demand routing protocol that uses route discovery and route maintenance through flooding of route request and route reply packets. Key aspects covered include: how DSR performs route discovery by broadcasting route requests; how the destination responds with a route reply listing the full end-to-end path; how nodes cache routes for potential future use; and how route errors trigger new route discovery if needed. DSR optimization through aggressive route caching is also discussed to speed up routing.
This document summarizes several routing protocols for ad hoc wireless networks. It describes the challenges in this domain including dynamic topologies and limited resources. It then categorizes and explains several types of routing protocols, including proactive protocols like DSDV, reactive protocols like AODV and DSR, hybrid protocols like ZRP, and geographic routing. It provides details on the route discovery and maintenance mechanisms of some of these prominent protocols. It also discusses theoretical limits on network capacity and the impact of mobility and hierarchy.
The document discusses routing protocols for mobile ad hoc networks (MANETs). It begins by defining MANETs and their unique characteristics, such as moving nodes, wireless links, and power constraints. Some key challenges for MANET routing protocols are the need for dynamic routing due to frequent topology changes and minimizing routing overhead. The document then discusses various categories of MANET routing protocols, including reactive protocols like DSR and AODV, proactive protocols, and hybrid and location-based protocols. It provides more detailed explanations of the route discovery and maintenance processes for DSR and AODV.
AODV and DSR are two routing protocols evaluated. AODV uses an on-demand approach where route requests are broadcast to discover paths between source and destination. Intermediate nodes record reverse paths for routing replies. When a link fails, a notification is sent to update routes. DSR stores source routes in packet headers. Route discovery broadcasts requests to build source routes, and route maintenance uses route error packets to update routes when failures occur. The performance of these protocols was analyzed using a simulation tool.
A Study on Ad Hoc on Demand Distance Vector AODV Protocolijtsrd
Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-4 , June 2019, URL: https://www.ijtsrd.com/papers/ijtsrd24006.pdf
Paper URL: https://www.ijtsrd.com/computer-science/computer-network/24006/a-study-on-ad-hoc-on-demand-distance-vector-aodv-protocol/dr-r-madhanmohan
Performance Comparison of AODV and DSDV Routing Protocols for Ad-hoc Wireless...Narendra Singh Yadav
This document compares the performance of two routing protocols for mobile ad hoc networks: Destination Sequenced Distance Vector (DSDV) and Ad Hoc On-Demand Distance Vector (AODV). It presents the results of simulations run using the ns-2 network simulator. The simulations varied the number of nodes, pause time (mobility rate), and number of data sources. The performance metrics measured were packet delivery ratio, average end-to-end delay, and normalized routing load. The results showed that AODV had higher packet delivery ratios and lower routing loads than DSDV. However, AODV experienced higher delays than DSDV due to its on-demand route discovery process. DSDV performed better in low
Mobility and Node Density Based Performance Analysis of AODV Protocol for Adh...IDES Editor
A mobile ad-hoc network (MANET) is a collection of
mobile nodes, which communicate over radio. These networks
have an important advantage; they do not require any
existing infrastructure or central administration. Therefore,
mobile ad-hoc networks are suitable for temporary
communication links. This flexibility, however, comes at a
price: communication is difficult to organize due to frequent
topology changes. In this paper we propose on-demand
routing algorithm for mobile, multi-hop ad-hoc networks. The
algorithm is based on ant algorithms, which are a class of
swarm intelligence. The main goal in the design of the
algorithm is to reduce the overhead for routing. Furthermore,
in this paper the performance of AODV protocol is analyzed
by varying mobility and node density parameters through
simulation of results ns2 simulator.
implementation of sinkhole attack on DSR protocolAtul Atalkar
This document outlines a dissertation seminar on implementing a sinkhole attack in the DSR routing protocol for mobile ad hoc networks (MANETs). It begins with introductions to MANETs and the DSR protocol, explaining their key characteristics and operations. The document then discusses sinkhole attacks, how they work in DSR networks, and their impacts on network performance metrics like packet delivery ratio and end-to-end delay. It proposes using the ns-2 network simulator to model and analyze the effects of sinkhole attacks on DSR routing in MANETs.
This document analyzes the performance of different routing protocols (AODV, DSR, DSDV) under various mobility models (random waypoint, random direction, random walk) and node speeds in mobile ad hoc networks. It finds that reactive protocols like AODV and DSR generally have higher packet delivery ratios than proactive DSDV, but end-to-end delays vary depending on the mobility model and node speed. The document proposes an algorithm to select the best routing protocol based on whether data delivery or time is the higher priority, and whether nodes are stationary or mobile. DSDV is preferred when data delivery is most important, while DSR performs better for time-critical applications.
The document discusses designing energy efficient routing protocols for mobile ad hoc networks (MANETs). It outlines several key points:
- MANETs are infrastructureless wireless networks formed by mobile nodes without centralized administration. Routing in MANETs is challenging due to the dynamic topology.
- Several routing protocols for MANETs are studied, including AODV, DSR and protocols that optimize power consumption like EPAR.
- The performance of these protocols is evaluated using MATLAB simulations based on metrics like packet delivery ratio, delay and throughput. The goal is to design a protocol that maximizes network lifetime by choosing routes with minimum total transmission power while ensuring nodes have sufficient battery capacity.
The document discusses routing protocols in mobile ad hoc networks. It describes the characteristics of ad hoc networks and why routing is different compared to traditional networks due to factors like host mobility and dynamic topology. The document categorizes and explains examples of different types of routing protocols including table-driven, on-demand, and hybrid protocols. It provides examples of specific protocols like DSDV, AODV, DSR, and ZRP and compares their key aspects.
To improve the QoS in MANETs through analysis between reactive and proactive ...CSEIJJournal
A Mobile Ad hoc NETwork (MANET), is a self-configuring infra structure less network of mobile devices
connected by wireless links. ad hoc is Latin and means "for this purpose". Each device in a MANET is free
to move independently in any direction, and will therefore change its links to other devices frequently. Each
must forward traffic unrelated to its own use, and therefore be a router. The primary challenge in building
a MANET is equipping each device to continuously maintain the information required to properly route
traffic. QOS is defined as a set of service requirements to be met by the network while transporting a
packet stream from source to destination. Intrinsic to the notion of QOS is an agreement or a guarantee by
the network to provide a set of measurable pre-specified service attributes to the user in terms of delay,
jitter, available bandwidth, packet loss, and so on. The analysis is mainly between proactive or table-driven
protocols like OLSR (Optimized Link State Routing) viz DSDV (Destination Sequenced Distance Vector) &
CGSR (Cluster Head Gateway Switch Routing) and reactive or source initiated routing protocols viz
AODV (Ad hoc on Demand distance Vector) & DSR (Dynamic Source Routing). The QoS analysis of the
above said protocols is simulated on NS2 and results are shown thereby.
Comparative Analysis of MANET Routing Protocols and Cluster Head Selection Te...IJERA Editor
Mobile Ad-hoc Network is a kind of wireless network. It is a backbone of new generation advanced communication technology. MANET is an ideal applicant for rescue and emergency situation due to its independence of connected devices of fixed wires. This paper represents a work on trust based system in MANET cluster that can be used to improve the performance of the network even in the existence of not trusted nodes. In the cluster architecture, cluster head and gateway nodes form a communication for routing among neighbouring clusters. But selection of cluster head is the important problem in dynamic Ad-hoc network because cluster head work as coordinator in clustered architecture. In this work, some values have used correspond to the threshold values of forward packet and dropped packet of each node within the network cluster. These values have been used dynamically updated every time and the node is selected as cluster head. In this technique of selecting the node as cluster head, the node which has maximum trusted value is elected as cluster head and this information is updated in every node’s trusted table. After implementation of our desired work, the proposed Dynamic Trust Evaluation of Cluster Head (DTE-CH) technique is analysed with traditional routing protocols and traditional clustering technique viz. Highest Degree Algorithm. The simulation is done by using network simulator software on the basis of different performance metrics throughput, packet delivery ratio, routing overhead, packet drop, average end to end delay and remain energy. Simulation result presents that proposed DTE-CH technique improves the performance of network as compare to most suitable existing AODV MANET protocol based technique as well as traditional highest degree clustering technique.
Network Surveillance Based Data Transference in Cognitive Radio Network with ...IRJET Journal
The document compares different wireless routing protocols to find the most energy efficient for creating a cognitive radio network model with attacker nodes. It first describes cognitive radio networks and their ability to dynamically access unused radio spectrum. It then summarizes the characteristics of reactive, proactive, and hybrid routing protocols. Reactive protocols determine routes on demand through flooding, while proactive protocols constantly update routing tables. The document analyzes the ad hoc on-demand distance vector (AODV) and dynamic source routing (DSR) reactive protocols as well as the destination sequenced distance vector (DSDV) and optimized link state (OLSR) proactive protocols. It aims to compare these protocols and determine the most energy efficient for the cognitive radio network model.
Network Surveillance Based Data Transference in Cognitive Radio Network with ...IRJET Journal
This document compares different wireless routing protocols to find the most energy efficient for creating a cognitive radio network model with attacker nodes. It analyzes reactive, proactive, and hybrid routing protocols including AODV, DSR, DSDV, OLSR, and a hybrid protocol. Simulation results show the hybrid protocol consumes the least energy compared to other protocols, making it well-suited for an energy efficient cognitive radio network model.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Low power architecture of logic gates using adiabatic techniquesnooriasukmaningtyas
The growing significance of portable systems to limit power consumption in ultra-large-scale-integration chips of very high density, has recently led to rapid and inventive progresses in low-power design. The most effective technique is adiabatic logic circuit design in energy-efficient hardware. This paper presents two adiabatic approaches for the design of low power circuits, modified positive feedback adiabatic logic (modified PFAL) and the other is direct current diode based positive feedback adiabatic logic (DC-DB PFAL). Logic gates are the preliminary components in any digital circuit design. By improving the performance of basic gates, one can improvise the whole system performance. In this paper proposed circuit design of the low power architecture of OR/NOR, AND/NAND, and XOR/XNOR gates are presented using the said approaches and their results are analyzed for powerdissipation, delay, power-delay-product and rise time and compared with the other adiabatic techniques along with the conventional complementary metal oxide semiconductor (CMOS) designs reported in the literature. It has been found that the designs with DC-DB PFAL technique outperform with the percentage improvement of 65% for NOR gate and 7% for NAND gate and 34% for XNOR gate over the modified PFAL techniques at 10 MHz respectively.
Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapte...University of Maribor
Slides from talk presenting:
Aleš Zamuda: Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapter and Networking.
Presentation at IcETRAN 2024 session:
"Inter-Society Networking Panel GRSS/MTT-S/CIS
Panel Session: Promoting Connection and Cooperation"
IEEE Slovenia GRSS
IEEE Serbia and Montenegro MTT-S
IEEE Slovenia CIS
11TH INTERNATIONAL CONFERENCE ON ELECTRICAL, ELECTRONIC AND COMPUTING ENGINEERING
3-6 June 2024, Niš, Serbia
ACEP Magazine edition 4th launched on 05.06.2024Rahul
This document provides information about the third edition of the magazine "Sthapatya" published by the Association of Civil Engineers (Practicing) Aurangabad. It includes messages from current and past presidents of ACEP, memories and photos from past ACEP events, information on life time achievement awards given by ACEP, and a technical article on concrete maintenance, repairs and strengthening. The document highlights activities of ACEP and provides a technical educational article for members.
Understanding Inductive Bias in Machine LearningSUTEJAS
This presentation explores the concept of inductive bias in machine learning. It explains how algorithms come with built-in assumptions and preferences that guide the learning process. You'll learn about the different types of inductive bias and how they can impact the performance and generalizability of machine learning models.
The presentation also covers the positive and negative aspects of inductive bias, along with strategies for mitigating potential drawbacks. We'll explore examples of how bias manifests in algorithms like neural networks and decision trees.
By understanding inductive bias, you can gain valuable insights into how machine learning models work and make informed decisions when building and deploying them.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
3. Ad Hoc Networks
Wireless networks can be divided in two fundamental
categories:
Infrastructure-based
Wireless clients connecting to a base-station (APs,
Cell Towers) that provides all the traditional network
services (routing, address assignment)
Infrastructure-less
The clients themselves must provide all the traditional
services to each other
4. Ad Hoc Networks
Ad-hoc networks main features:
Decentralized
Do not rely on preexisting infrastructure
Each node participates in routing by
forwarding data to neighbor nodes
Fast network topology changes due to nodes’
movement
5. Ad Hoc Networks
Why do we need ad-hoc networks?
More laptop users
More smartphones users (e.g.. Android phones,
iPhones)
More devices with Wi-Fi-support (e.g.. televisions, hi-
fi, home-theaters, media servers etc.)
Moving users, vehicles, etc.
Outdoors places
In all these occasions there is no centralized
infrastructure (such APs)
So ad-hoc network is a necessity
8. Ad-hoc routing algorithms
Hottest routing algorithm categories:
Pro-active (table-driven) routing
Maintains fresh lists of destinations & their routes by periodically
distributing routing tables
Disadvantages:
1. Respective amount of data for maintenance
2. Slow reaction on restructuring and failures
(e.g. OSLR, DSDV)
Reactive (on-demand) routing
On demand route discovery by flooding the network with Route
Request packets
Disadvantages:
1. High latency time in route finding
2. Flooding can lead to network clogging
(e.g. AODV, DSR)
10. Outline
Ad-Hoc networks
Ad-hoc routing algorithms
Ad-Hoc on-demand Distance Vector Routing (AODV)
General info
Path Discovery
Path Maintenance
Local Connectivity Maintenance
Conclusion
Dynamic Source Routing (DSR)
Comparison of AODV and DSR
11. (AODV) General info
Reactive algorithms like AODV create routes on-
demand. They must however, reduce as much as
possible the acquisition time
We could largely eliminate the need of periodically
system-wide broadcasts
AODV uses symmetric links between neighboring
nodes. It does not attempt to follow paths
between nodes when one of the nodes can not hear
the other one
12. (AODV) General info
Nodes that have not participate yet in any packet
exchange (inactive nodes), they do not maintain
routing information
They do not participate in any periodic routing table
exchanges
13. (AODV) General info
Each node can become aware of other nodes in its
neighborhood by using local broadcasts known as
hello messages
neighbor routing tables organized to :
1. optimize response time to local movements
2. provide quick response time for new routes
requests
14. (AODV) General info
AODV main features:
Broadcast route discovery mechanism
Bandwidth efficiently (small header information)
Responsive to changes in network topology
Loop free routing
15. Outline
Ad-Hoc networks
Ad-hoc routing algorithms
Ad-Hoc on-demand Distance Vector Routing (AODV)
General info
Path Discovery
Path Maintenance
Local Connectivity Maintenance
Conclusion
Dynamic Source Routing (DSR)
Comparison of AODV and DSR
16. (AODV) Path Discovery
Initiated when a source node needs to
communicate with another node for which it has no
routing info
Every node maintains two counters:
node_sequence_number
broadcast_id
The source node broadcast to the neighbors a
route request packet (called RREQ)
17. (AODV) Path Discovery
RREQ structure
<src_addr, src_sequence_#, broadcast_id, dest_addr,
dest_sequence_#, hop_cnt>
src_addr and broadcast_id uniquely identifies a RREQ
broadcast_id is incremented whenever source node
issues a RREQ
Each neighbor either satisfy the RREQ, by sending
back a routing reply (RREP), or rebroadcast the RREQ
to its own neighbors after increasing the hop_count by
one.
18. (AODV) Path Discovery
If a node receives a RREQ that has the same
<src_addr, broadcast_id> with a previous RREQ it
drops it immediately
If a node cannot satisfy the RREQ, stores:
Destination IP
Source IP
broadcast_id
Expiration time (used for reverse path process)
src_sequence_#
19. (AODV) Path Discovery
1. Reverse Path Setup
In each RREQ there are:
src_sequence_#
the last dest_sequence_#
src_sequence_# used to maintain freshness
information about the reverse route to the source
dest_sequnece_# indicates how fresh a route must
be, before it can be accepted by the source
20. (AODV) Path Discovery
1.Reverse Path Setup (continue)
As RREQ travels from source to many destinations, it
automatically sets up the reverse path, from all nodes
back to the source.
But how does it work?
Each node records the address of the neighbor from which it
received the first copy of the RREQ
These entries are maintained for at least enough time, for the
RREQ to traverse the network and produce a reply
21. (AODV) Path Discovery
1.Reverse Path Setup (continue)
U
D
Z
Y
W
S
V
S
D
Z
W
ZW
Source node
Destination node
Neighbor nodes
S sends RREQ
Figure 1
W, Y can not satisfy RREQ
i. Set up reverse path
ii. Rebroadcast RREQ to
neighbors
Z, V, U can not satisfy RREQ
i. Set up reverse path
ii. Rebroadcast RREQ to
neighbors
RREQ reached destination
Reversed path is fully set up
From which RREP can travel
back to S
22. (AODV) Path Discovery
2. Forward Path Setup
A node receiving a RREP propagates the first RREP
for a given source towards the source (using the
reverse path that has already established)
Nodes that are not in the path determined by the
RREP will time out after 3000 ms and will delete the
reverse pointers
23. (AODV) Path Discovery
2. Forward Path Setup (continue)
U
D
Z
Y
W
S
V
S
D
Z
W
WZ
Source node
Destination node
Z has a reversed path to W
Figure 2
ZW W has a forward path to Z
D replies with a
RREP to Z
Z receives RREP
and set up a
forward pointer
The same
for the
other
nodes
Time out
24. (AODV) Path Discovery
2. Forward Path Setup (Conclusion)
Minimum number of RREPs towards source
The source can begin data transmission as soon as
the first RREP received and update later its routing
information if it learns of a better route
25. Outline
Ad-Hoc networks
Ad-hoc routing algorithms
Ad-Hoc on-demand Distance Vector Routing (AODV)
General info
Path Discovery
Path Maintenance
Local Connectivity Maintenance
Conclusion
Dynamic Source Routing (DSR)
Comparison of AODV and DSR
26. (AODV) Path Maintenance
Movement of nodes not lying along an active path does NOT
affect the route to that path's destination
If the source node moves, it can simply re-initiate the route
discovery procedure
If the destination or some intermediate node moves, a
special RREP is sent to the affected nodes
To find out nodes movements periodic hello messages can be
used, or (LLACKS) link-layer acknowledgments (far less
latency)
27. (AODV) Path Maintenance
When a node is unreachable the special RREP that
is sent back towards the source, contains a new
sequence number and hop count of ∞
U
D
Z
Y
S
V
Z
W
Figure 3
Link between Z
and D fails
Z sents a
special RREP
So do W
So now source must find a new path. To do that, it sents a RREQ with a new greater
sequence number
28. Outline
Ad-Hoc networks
Ad-hoc routing algorithms
Ad-Hoc on-demand Distance Vector Routing (AODV)
General info
Path Discovery
Path Maintenance
Local Connectivity Maintenance
Conclusion
Dynamic Source Routing (DSR)
Comparison of AODV and DSR
29. (AODV) Local Connectivity
Maintenance
Nodes learn of their neighbors in one or two ways:
1. Whenever a node receives a broadcast from a
neighbor it update its local connectivity
information about this neighbor
2. If a neighbor has not sent any packets within
hello_interval it broadcasts a hello message,
containing its identity and its sequence number
30. (AODV) Local Connectivity
Maintenance
How hello messages work:
Hello messages do not broadcasted outside the
neighborhood because the contain a TTL (time to
leave) value of 1.
Neighbors that receive the hello message update
their local connectivity information to the node that
have broadcasted the hello message
31. (AODV) Local Connectivity
Maintenance
How hello messages work: (continue)
Receiving a hello from a new neighbor, or failing to
receive allowed_hello_loss (typically 2) consecutive
hello messages from a node previously in the
neighborhood, indicates that the local connectivity
has changed
32. Outline
Ad-Hoc networks
Ad-hoc routing algorithms
Ad-Hoc on-demand Distance Vector Routing (AODV)
General info
Path Discovery
Path Maintenance
Local Connectivity Maintenance
Conclusion
Dynamic Source Routing (DSR)
Comparison of AODV and DSR
33. (AODV) Conclusion
AODV main features:
Nodes store only the routes they need
Need for broadcast is minimized
Reduces memory requirements and needless
duplications
Quick response to link breakage in active routes
Loop-free routes maintained by use of destination
sequence numbers
Scalable to large populations of nodes
36. (DSR) General
Two main mechanisms that work together to allow the
discovery and maintainance of source routes:
Route discovery
Route maintainance
37. (DSR) General
Route discovery:
Is the mechanism by which a source node S, obtains
a route to a destination D
Used only when S attempt to send a packet to D and
does not already knows a route to D
38. (DSR) General
Route maintainance:
Is the mechanism by which source node S is able to
detect if the network topology has changed and can
no longer use its route to D
If S knows another route to D, use it
Else invoke route discovery process again to find a
new route
Used only when S wants to send a packet to D
39. (DSR) General
Each mechanism operate entirely on demand
DSR requires no periodic packets of any kind at any
level
Uni-directional and asymmetric routes support
(e.g. send a packet to a node D through a route and receive a
packet D from another route)
41. (DSR) Basic Route Discovery
When S wants to sent a packet to D:
it places in the header of the packet a source route
giving the sequence of hops that the packet should
follow on its way to D
S obtains a suitable source route by searching its route
table
If no route found for D, S initiate the Route Discovery
protocol to dynamically find a new route to D
42. (DSR) Basic Route Discovery
Sender
Broadcasts a Route Request Packet (RREQ)
RREQ contains a unique Request ID and the address of the
sender
Receiver
If this node is the destination node, or has route to the
destination send a Route Reply packet (RREP)
Else if is the source, drop the packet
Else if is already in the RREQ's route table,
drop the packet
Else append the node address in the RREQ's route table
and broadcast the updated RREQ
43. (DSR) Basic Route Discovery
U
D
Z
Y
W
S
V
S
D
Z
W
ZW
Source node
Destination node
Neighbor nodes
S sends RREQ
Figure 4
RREQ packet
Id=2, {S}
Id=2, {S}
Id=2, {S, W}
Id=2, {S, Y}
Id=2, {S, Y}
Id=2, {S, W, Z}
44. (DSR) Basic Route Discovery
When a RREQ reaches the destination node, a RREP
must be sent back to source
The destination node:
Examine its own Route Cache for a route back to source
If found, it use this route to send back the RREP
Else, the destination node starts a new Route Discovery
process to find a route towards source node
In protocols that require bi-directional links like 802.11, the
reversed route list of the RREQ packet can be used, in order to
avoid the second Route Discovery
46. (DSR) Basic Route Maintenance
Each node transmitting a packet:
is responsible for confirming that the packet has been received
by the next hop along the source route
The confirmation it is done with a standard part of MAC layer
(e.g. Link-level ACKs in 802.11)
If none exists, a DSR-specific software takes the
responsibility to sent back an ACK
When retransmissions of a packet in a node reach a maximum
number, a Route Error Packet (RERR) is sent from the node back
to the source, identifying the broken link
47. (DSR) Basic Route Maintenance
The source:
Removes from the routing table the broken route
Retransmission of the original packet is a function of
upper layers (e.g. TCP)
It searches the routing table for another route, or start
a new Route Discovery process
48. (DSR) Basic Route Maintenance
U
D
Z
Y
W
S
V
S
D
Z
W
ZW
Source node
Destination node
Neighbor nodes
Figure 5
RERR packet
Link fails
Intermediate
node sents a
RERR
RERR(Z, D)
RERR(Z, D)
Route Table
D: S, W, Z, D
V: S, Y, V
50. (DSR) Conclusion
Excellent performance for routing in multi-hop wireless
ad hoc networks
Very low routing overhead even with continuous rapid
motion, which scales to :
1. zero when nodes are stationary
2. the affected routes when nodes are moving
Completely self-organized & self-configuring network
Entirely on-demand operation. No periodic activity of any
kind at any level
53. Comparison of AODV and DSR
Main common features:
On-demand route requesting
Route discovery based on requesting and replying
control packets
Broadcast route discovery mechanism
54. Comparison of AODV and DSR
Main common features: (continue)
Route information is stored in all intermediate nodes
along the established path
Inform source node for a broken links
Loop-free routing
55. Comparison of AODV and DSR
Main differences:
DSR can handle uni and bi-directional links, AODV uses
only bi-directional
In DSR, using a single RREQ - RREP cycle, source and
intermediate nodes can learn routes to other nodes on
the route
DSR maintains many alternate routes to the destination,
instead of AODV that maintains at most one entry per
destination
56. Comparison of AODV and DSR
Main differences: (continue)
DSR doesn’t contain any explicit mechanism to expire
stale routes in the cache , In AODV if a routing table
entry is not recently used , the entry is expired
DSR can’t prefer “fresher” routes when faced multiple
choices for routes. In contrast, AODV always choose
the fresher route (based on destination sequence
numbers)
57. Comparison of AODV and DSR
Main differences: (continue)
DSR’s RREQ has variable length depending on the nodes
that the packet has traveled. AODV’s RREQ size is
constant
As a result DSR’s header overhead may increase as more
nodes become active, so we expect that AODV
throughput in those scenarios to be better
58. Comparison of AODV and DSR
Test bench set up:
100 nodes, some of them as sources
Nominal bit rate of 2 Mb/s
Nominal node range of 250 m
Continuously moving nodes
60. Comparison of AODV and DSR
Application and routing statistics for an example scenario for a network of 100
nodes with continuous mobility and 40 sources
Performance
metrics
DSR AODV
Packets delivered
/Packets sent (%)
56.88 83.66
Average delay (s) 1.36 0.26
Routing Packets DSR AODV
Route requests 37774 228094
Route replies 82710 17753
Route errors 26591 9808
Total 147075 255655
61. Conclusion
DSR outperforms AODV in less stressful situations
(i.e., smaller number of nodes and lower load and/or
mobility)
AODV outperforms DSR in more stressful situations
(e.g., more load, higher mobility)
DSR commonly generates less routing load than AODV
Poor delay and throughput of DSR due to lack of any
mechanism to expire stale routes or determine the
freshness of routes