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DIANE Project

Universität Karlsruhe. An approach to Support Service Discovery in Mobile Ad-hoc Networks - Concept and Simulation -. Diplomarbeitsvortrag Eduardo Ponz. Betreuer: Birgitta König-Ries, Michael Klein. Universität Karlsruhe Institute for Program Structures and Data Organization. DIANE Project.

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DIANE Project

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  1. Universität Karlsruhe An approach to Support Service Discovery in Mobile Ad-hoc Networks - Concept and Simulation - Diplomarbeitsvortrag Eduardo Ponz Betreuer: Birgitta König-Ries, Michael Klein Universität Karlsruhe Institute for Program Structures and Data Organization DIANE Project http://www.ipd.uni-karlsruhe.de/DIANE

  2. Mobile phone PDA Laptop Introduction • Mobile devices are becoming very popular Introduction Scenario Concept - Information - Protocols Implementation Summary • We want to link these devices in mobile ad-hoc networks and offer services • How do we search for a service in such a network?

  3. Problems with Mobile Ad-hoc Networks Introduction Scenario Concept - Information - Protocols Implementation Summary • Highly dynamic topology due to • - node movement • - node fluctuation • - appearing obstacles • No dedicated server, no physical infrastructure

  4. Service Ring (1) DIANE Approach: Service Rings Introduction • Group nodes offering similar services into a Service Ring (SR) Scenario Concept - Information - Protocols Implementation Summary • One node of the ring becomes the Service Access Point (SAP) • This node has the description of all the services of the ring

  5. Service Ring Model Service Ring (2) Many aspects have to be considered in the service ring model: Introduction Scenario Concept - Information - Protocols • Service description • Service discovery Implementation Summary • Service integration • Motivation

  6. Service Discovery Service discovery implies many different aspects Introduction Scenario • Ring and Service Information • - What information should be stored in the nodes? Concept - Information - Protocols • Initialization Protocol • - How is a service ring built? Implementation Summary • NodeRouting Protocol • - How do we find the proper service inside a service ring? • Ring Routing Protocol • - How do we find the proper service ring? • Actualization Protocol • - How should the system react to device movement and fluctuations?

  7. Node Information Service Discovery • Node ID, Cycle ID • Reachable nodes • Predecessor and Successor Node Routing Protocol • Ring Information • Ring ID • Service Type of the SR Ring Routing Protocol Service Description Out of the scope of the Diploma Thesis Ring and Service Information Information about the service ring has to be locally stored in the nodes Introduction Scenario Concept - Information - Protocols Implementation Summary • Service Information • Services offered by the node

  8. If SR then CONNECT to SR • else SET node as SAP CONNECT: If there is only one node of the SR reachable then • Build a bridge If there are more nodes of the SR reachable then • Insert into SR between the two closest linked nodes Initialization Protocol How to build a service ring from scratch Introduction Scenario - One node appears SAP Concept - Information - Protocols - A second node appears - A third node appears Implementation Service Ring? SR? We ask if there is any SR nearby Summary SR?

  9. D Service B Service C Service A Service D Node Routing Protocol (1) How to find the proper service inside a SR Introduction • Routing in a simple SR is trivial but... Scenario Concept - Information - Protocols No X‘s Successor Service D? Node X Yes, but NOT me • Each node has one successor and one predecessor Implementation Thanks! Summary X‘s Predecessor • We only have to route the message to the successor node YES No • How do we deal with intricate rings?

  10. Node Routing Protocol (2) Service rings may be intricate Introduction Scenario Concept - Information - Protocols C2 C4 Implementation C1 Summary C5 C3 • Some nodes have more than one successor and predecessor • Some nodes have twice the same successor or predecessor To properly route a message: - We divide the service ring into cycles - A message traveling along the SR will keep track of which cycles are already visited

  11. Node Routing Protocol (3) Example of routing a message: Routing complete! Introduction Service D? Scenario Concept - Information - Protocols C2 C4 Implementation C1 Summary C5 C3 Algorithm for nodes with many successors: • Continue in the same cycle - If we have twice the same successor - If the other cycles have been partially visited • Jump to another cycle - If the other cycle is a not visited bridge - If the other cycle is a not visited cycle

  12. Yellow service Blue service Green service Indigo service We have many different service rings that offer different services Ring of SRs RingRoutingProtocol How do we find the proper SR? Introduction Scenario Concept - Information - Protocols Implementation Summary The SAPs are connected with each other • The SAPs store the information about ring routing • A message can now jump to other SRs

  13. Actualization Protocol (1) Reactions to device movements and fluctuations Introduction Scenario Concept - Information - Protocols Implementation Summary Typical node fluctuations are: • Movement • Into a SR • Out of a SR • Logging • Login into a SR • Logout of a SR • Sudden disconnection

  14. B Backward routing I I I Actualization Protocol (2) Example of sudden disconnection algorithm: Introduction - Node B vanishes Scenario - Node A needs to link with C Concept - Information - Protocols C is not reachable! F A Implementation Summary - Node C looks for reachable nodes X E - Node C requests information - Reachable nodes send info - C processes the info and chooses the best node D C - C sends control message to X - X marks C as successor Note: Backward routing should be only used if everything else fails - X sends control message to A - A marks X as successor - The SR is successfully closed

  15. Implementation A simulation of the Node Routing Protocol in a service ring is currently under development Introduction Scenario Concept - Information - Protocols • QualNet is the network simulator used for this purpose Implementation Summary - QualNet models complex wireless networks - There are pre-written protocol models - Custom protocols can be developed

  16. Summary and Future Work Summary: Introduction • A basic mechanism to service discovery has been proposed Scenario Concept - Information - Protocols ü Implementation ü Summary ü ü ü Future Work: • Optimization to the proposed protocols • Implementation of all the protocols in QualNet • Prototype in a real scenario

  17. Are there any questions? Thank you! Thank you for your attention! More information on our project web page: http://www.ipd.uni-karlsruhe.de/DIANE

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