Fault-Tolerant Papers Broadband Network & Mobile Communication Lab Course: Computer Fault-Tolerant Speaker: 邱朝螢 Date: 2004/4/20

Broadband Network & Mobile Communication Lab 2 Papers Based on DSR Performance Enhancement of Ad Hoc Networks with Localized Route Repair (2003 IEEE Transaction Journal) An Extended Dynamic Source Routing Scheme in Ad Hoc Wireless Networks (2002 IEEE Proceedings of the 35th Annual Hawaii International Conference)

Broadband Network & Mobile Communication Lab 3 Papers Based on AODV AODV-BR : Backup Routing in Ad Hoc Networks (2000 Proceedings of the IEEE Wireless Communications and Networking Conference) AODV-PA : AODV with Path Accumulation (2003 IEEE International Conference)

Broadband Network & Mobile Communication Lab 4 Outline Introduction concept of the four papers. Simulation of papers. Compare the papers.

Performance Enhancement of Ad Hoc Networks with Localized Route Repair

Broadband Network & Mobile Communication Lab 6 Request Zone : The zone in which the route-repair packet propagates is known as the “request zone” LRR consists of two major component The radius of request zone is two hops Next-to-Next (NN) Localized Route Repair (LRR)

Broadband Network & Mobile Communication Lab 7 destination source A B C D Request Zone

Broadband Network & Mobile Communication Lab 8 Request Zone destination source A B C D hop1 hop2

Broadband Network & Mobile Communication Lab 9 Next-to-Next (NN) Information about next-to-next node is stored at each intermediate node along the path.

Broadband Network & Mobile Communication Lab 10 Localized Route Repair (LRR) A node start a timer when it sends out the non- propagating route request. Timer times out, if it receives a reply It sends all the subsequent packets through that node Else, it exits and allows the route maintenance mechanism to find a new route It also piggybacks the information about the change in route on one of data packets and an acknowledgment toward the source.

Broadband Network & Mobile Communication Lab 11 Localized Route Repair (LRR) Thus, the route is repaired and the information is distributed to all the nodes on the route. The strategy repairs the route on the fly in the shortest possible time, since the data packets are cached at the intermediate node for that time, retransmission of the partial data by the source is avoided.

Broadband Network & Mobile Communication Lab 12 Simulation Random Waypoint Model Simulation Range 1500*300 meters Number of node in the range Random creating 50 nodes Traffic source CBR (Content Bit-Rate) Pause time 0~900 second

Broadband Network & Mobile Communication Lab 13 Simulation Metric Routing Overhead / Pause Time Packet Delivery Ratio / Pause Time Average Delay / Pause Time (End-to-End delay of data packets)

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An Extended Dynamic Source Routing Scheme in Ad Hoc Wireless Networks

Broadband Network & Mobile Communication Lab 18 Extended Dynamic Source Routing Find two disjoint path between the source and the destination of a routing process without introducing extra overhead. The paper proposal that modifies DSR’s RREQ process Two disjoint route path Black route (nodes exclude source and destination in the route color black ) White route (nodes exclude source and destination in the route color white )

Broadband Network & Mobile Communication Lab 19 Extended Dynamic Source Routing Each intermediate node can be colored only once and the destination can be colored twice with one for each color. Each host maintain a list of (source, destination, request_id, color)

Broadband Network & Mobile Communication Lab 20 Extended Dynamic Source Routing Each sender s initially broadcasts two request (s, d, id, black) and (s, d, id, white) When an intermediate host v receives a route packet (s, d, id, color) If v has been marked for (s, d, id) then the request will discarded. Else, the request is kept for △ time before making v for (s, d, id) If v does not receive a route request (s, d, id, ‘color), then v is marked color for (s, d, id) Else, v is randomly marked either white or black

Broadband Network & Mobile Communication Lab 21 destination source EDSR

Broadband Network & Mobile Communication Lab 22 Simulation Not in NS2 Simulation Range 100 * 100 meters Number of node in the range Random creating 0~100 nodes Node radius 15, 25, 50, 75

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Broadband Network & Mobile Communication Lab 25 Compare Above Two Papers Modify DSR First paper modifies flooding range when a RERR occurs. Second paper modifies route discovery/reply. Purpose First paper presents a Localized Route Repair ( LRR) technique which repairs a route on the fly as soon as it is broken. Second paper presents a technique to find two disjoint route when source node want to forward data to destination node.

AODV-BR : Backup Routing in Ad Hoc Networks

Broadband Network & Mobile Communication Lab 27 AODV-BR The paper proposes a scheme to improve AODV by creating a mesh and providing multiple alternate routes. The paper proposal that modifies AODV’s RREP process.

Broadband Network & Mobile Communication Lab 28 AODV-BR Overhear A node promiscuously “overhears” packets that are transmitted by their neighboring nodes. A node obtains alternate path information and becomes part of the mesh as follows. When a node that is not part of the route overhears a RREP packet not directed to itself transmitted by a neighbor, it records that neighbor as the next hop to the destination in its alternate route table.

Broadband Network & Mobile Communication Lab 29 destination source A B D RREQ C

Broadband Network & Mobile Communication Lab 30 destination source A B D RREP C E E Overhear RREP F

Broadband Network & Mobile Communication Lab 31 RERR destination source A C D B D broadcast to find a route to F E F

Broadband Network & Mobile Communication Lab 32 Simulation Random Waypoint Model Simulation Range 1500*300 meters Number of node in the range Random creating 50 nodes Traffic source CBR (Content Bit-Rate) Pause time 0~300 second

Broadband Network & Mobile Communication Lab 33 Simulation Metric Packet Delivery / Pause Time End-to-End Delay / Pause Time Number of Data Transmitted/Data Received / Pause Time (Routing Overhead)

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AODV-PA : AODV with Path Accumulation

Broadband Network & Mobile Communication Lab 38 AODV and DSR RREQ Process AODV DSR ABCDE AA, BA,B,CA,B,C,D ABCDE

Broadband Network & Mobile Communication Lab 39 AODV Routing table entry Destination Next hop Number of hops (metric) Sequence number for the destination Active neighbors for this route Expiration time for the route table entry

Broadband Network & Mobile Communication Lab 40 Improving AODV AODV Advantage Nodes periodically exchange hello message. Nodes (not on a selected path) don’t maintain routing information or participate in routing table exchanges. AODV Disadvantage Nodes can not know other nodes exclude it’s neighbors. A old route in source node is difficult to maintain.

Broadband Network & Mobile Communication Lab 41 Path Accumulation in AODV ABCDE RREQ AA, BA,B,CA,B,C,D ED,EC,D,EB,C,D,E Node C, D, E can get the route information to maintain it ’ s routing table

Broadband Network & Mobile Communication Lab 42 Simulation Random Waypoint Simulation Range 1000*1000 meters with 50 nodes 1500*1500 meters with 100 nodes Traffic source CBR (Content Bit-Rate) Total time 600 second

Broadband Network & Mobile Communication Lab 43 Simulation Metric Packet Delivery Ratio Normalized Routing Load (Routing Overhead) End-to-End Delay of Data packets

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Broadband Network & Mobile Communication Lab 50 Compare Above Two Papers Modify DSR First paper modifies RREP Second paper combine AODV and DSR Purpose First paper establish alternate route table to find a new route when the route occur failure. Second paper employ DSR’s RREQ format to improve AODV’s routing table.