Fault Tolerant Routing in Mobile Ad hoc Networks
Yuan Xue and Klara Nahrstedtxue,[email protected] Science DepartmentUniversity of Illinois at Urbana-Champaignhttp://cairo.cs.uiuc.edu
This research was supported by the ONR MURI NAVY CU 37515-6281 grant, and the NSF EIA 99-72884EQ grant. Any opinions, findings, and conclusions are those of the authors and do not necessarily reflect the views of the above agencies
Outline
MotivationModel and problem formulationAlgorithm and its analysisExampleDiscussionSimulation resultsRelated work Conclusion
Motivation
Most existing routing protocols need mobile nodes to cooperate with each other.If there exist non-cooperative nodes or faulty nodes, then the performance of the current routing protocols will degrade.
Our approach – tolerating faulty nodes
Observation: Ad hoc networks are highly redundant – there
exist multiple paths between source and destination.
Approach: Exploring the network redundancy through
multipath routing.
Challenge: Trade off between effectiveness (packet
delivery rate) and efficiency (packet overhead).
ModelNetwork Model
Faulty Node Model
Problem FormulationAssumption Perfect knowledge of faulty nodes behaviors
Packet-delivery-rate-constrained overhead-minimization problem (PCOO)
PCOO problem is NP-complete
E2FT Algorithm (I)Challenges revisit No precise knowledge of nodes behaviors NP-complete complexity
Algorithm overview Route estimation (end-to-end estimation)
Estimate Route selection
Select so that and can be reduced
E2FT Algorithm (II) – route estimation
raw estimation Estimation Raw estimation Iterative estimation method
Problem: different estimation accuracy
-estimation Definition
Property
E2FT Algorithm (III) – route selection
Initially
Progressive route refinement via Confirmation
Confirm a path p if Dropping
Drop a path pmin if satisfies
Property analysis
Bounded packet delivery rate
Bounded route selection overhead
Example (I)
Example (II)
DiscussionAccommodation to node mobility Node estimation (max-min rule)
Path estimation
Accommodation to node behavior dynamics Soft state – long term dynamics Dynamics during estimation
Route set discovery Needs to integrate with route discovery protocol
Simulation SetupNetwork settings 700m*700m 50 nodes M faulty nodes – simulation parameter
Mobility model Random waypoint Speed: 20m/s Pause time – simulation parameter
Default values
Result (I) – packet delivery rate
Result (II) -- overhead
Result (III) – node mobility
Result (IV) – node mobility
Other Approaches
Protection SAR (Security-Aware Routing) by S. Yi et al. Secure route discovery by Papadimitratos and
Hass URSA (Ubiquitous and Robust Security
Architecture) by H. Luo et al.
Detection Intrusion detection by Zhang and Lee Detect misbehaving nodes by S. Marti et al.
Toleration Blind multipath routing by Z. Hass et al.
Conclusion
Fault tolerant routing is an effective approach to address the problem of faulty/misbehaving nodes in ad hoc networksE2FT can obtain high and stable packet delivery rate and acceptable additional overhead simultaneously
Thank you very much!
