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Mobile IPv6-Based Ad Hoc Networks: Its Development and Application. Advisor: Dr. Kai-Wei Ke Speaker: Wei-Ying Huang. Outline. Introduction MANET Tree Overlay Management Routing Protocol Mobile IPv6 Support P2P Information Sharing System Implementation Conclusion Reference.
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Mobile IPv6-Based Ad Hoc Networks:Its Development and Application Advisor: Dr. Kai-Wei Ke Speaker: Wei-Ying Huang
Outline • Introduction • MANET Tree Overlay Management • Routing Protocol • Mobile IPv6 Support • P2P Information Sharing System • Implementation • Conclusion • Reference
Introduction • IEEE 802.11 WLAN interface cards • Infrastructure mode • Ad Hoc mode • Ad Hoc mode more flexible, but its aim is not to connect to the Internet
Introduction (cont) • Goal: Allow MN form an IPv6-based MANET flexibly and access the global IPv6 Internet • MN form a self-organization, self-addressing MANET into a tree structure rooted with an Internet gateway, referred to as the access router (AS) • Specially designed unicast/multicast routing protocols for MANETs, which are more suitable for IPv6
Introduction (cont) • Using many small-size MANETs connected to the global Internet via access routers (ARs) • There exist several tree-based multicast routing protocols for MANET, but they consume excessive overhead to maintain a great quantity of source trees
Introduction (cont) • Each mobile device will move around, but only at walking speed (low mobility, less than 2 m/s) • Mobile IPv6 will be supported such that a mobile node can move from one MANET to another
Introduction (cont) • P2P applications are very important in the future • PDI can efficiently search files scattered over mobile devices by querying locally • ORION combines application layer query and overlay network layer route discovery to ensure accurate search and low overhead • These solutions are not scalable and curtail throughput as the size of a MANET grows.
Introduction (cont) • Designed a distributed, but structured P2P information sharing system over our IPv6-based MANET using the distributed hashing table (DHT) technique • Note that this design is under the mobile nodes only move in low speed
Introduction • MANET Tree Overlay Management • Routing Protocol • Mobile IPv6 Support • P2P Information Sharing System • Implementation • Conclusion • Reference
JOIN Procedure • It sends out a JOIN REQUEST message to its neighbors • Each neighbor will select a unique address among its current child nodes and response the JOIN message with the selected address • Upon receiving a JOIN request, a neighbor node with address x1,…,xi will select an address x1,…,xi,xi+1
JOIN Procedure • If the new node does not receive any response within a fixed time, it will keep sending the JOIN REQUEST message until it got a response • Select the one near the tree root, because it results in a flat tree which yields shorter routing path.
IPv6 Address Configuration • A mobile node may configure its IPv6 link-local or global address by attaching a network prefix to its 64-bit network interface ID • Use a mobile node’s logic address as its 64-bit interface ID when configuring its IPv6 addresses (link-local or global)
IPv6 Address Configuration • For example, if the logical address of a node is “1.2.1,” its link local address will be set to FE80::1210:0:0:0/64 • The 64-bit interface ID is divided into sixteen levels, each with four bits. That is, each node can have at most 15 child nodes, and the height of overlay tree is at also most 16
Maintain the Tree Overlay • Heartbeat (for child) • Each node regularly sends a heartbeat to its parent node, and node should receive an ACK from its parent • If a child node does not receive the ACK message, it increases its heartbeat-ACK-missed counter • If the counter is larger than a certain threshold, it assumes that its parent has crashed or moved away
Maintain the Tree Overlay • Parent maintenance at the child node
Maintain the Tree Overlay • child-heartbeat timer (for parent) • If a child does not send a heartbeat for a long time, the child-heartbeat timer will expire • the parent node assumes that the child has crashed or moved away, then the resource and address of the child will then be released.
Maintain the Tree Overlay • Child maintenance at the parent node
Introduction • MANET Tree Overlay Management • Routing Protocol • Mobile IPv6 Support • P2P Information Sharing System • Implementation • Conclusion • Reference
Routing Protocol • To avoid additional overhead, the proposed routing protocol does not need to find routing path on demand • Each mobile node maintains a routing table with two kinds of information: default routing and soft state routing cache
Unicast Routing Protocol • default routing • Longest prefix matching is used to determine how to forward a packet to its destination • soft state routing cache • mobile node can improve the routing efficiency by adding its neighbor information into the routing cache
Multicast Routing Protocol • Multicast is especially important for sending ICMPv6 messages • default routing • Forward by using flooding and stop at the leaf nodes • unidirectional routing cache • A direction flag, which can be set to up, or down • Direction flag of a multicast packet sent by the AR, or a MN, is set to down, or up, respectively
Introduction • MANET Tree Overlay Management • Routing Protocol • Mobile IPv6 Support • P2P Information Sharing System • Implementation • Conclusion • Reference
Mobile IPv6 Support • MN joins a MANET and gets a global IPv6 address at first • MN moves to another MANET where it will perform the JOIN procedure again to join the new MANET • After joined the new MANET, it will receive a new global prefix and form its new global IPv6 address, which will become its CoA • Then send binding update to original home agent and corresponding nodes
Introduction • MANET Tree Overlay Management • Routing Protocol • Mobile IPv6 Support • P2P Information Sharing System • Implementation • Conclusion • Reference
distributed hashing table (DHT) • Logic address is used as the node id (key) of the P2P system • a node uses the filename or some keywords as the input to a hash function • output of the hash function, called a key, will correspond to the logic address of a mobile node which will be responsible for storing the information of the shared object
Introduction • MANET Tree Overlay Management • Routing Protocol • Mobile IPv6 Support • P2P Information Sharing System • Implementation • Conclusion • Reference
Implementation • Implementation of Tree Overlay Maintenance Protocols • Implementation of Routing Protocol • Implementation of P2P Information Sharing System
Performance Evaluation • Unicast • Control Message Overhead • Delivery Ratio = the number of data packets actually received by receivers over the number of data packets sent by sources • Multicast • Number of Nodes • Delivery Ratio = the number of nonduplicated data packets actually received by receivers over the number of packets supposed to be received by receivers.
Environment • Using the Qualnet network simulator • Our simulation models a network 50 ~ 200 MN placed randomly within a 1000 x 1000 area • Radio propagation range for each node is 200 meters and channel capacity is 11 Mb/s. • The random way point model is adopted as our mobility model in which the pause time is varied from 0 to 400 s • Traffic model uses constant bit rate (CBR) source and MANET consists of 500 CBR sources, each with sending rate of 1 packet/s and the packet size is 1024 bytes • Simulate the scenarios that Internet traffic contributes 80% of the traffic • Mobility speed is varied from 0 to 10 m/s • Multiple runs, each runs for 600 simulation times, are conducted for each scenario • The collected results are averaged over all runs and 95% confidence intervals are calculated.