1 / 17

ASWP – Ad-hoc Routing with Interference Consideration

ASWP – Ad-hoc Routing with Interference Consideration. June 28, 2005. Scenarios. Deploy troops into field Goals QoS Traffic classes, flow requirements Scalable Difficulty Interference. Outline. Problem description Interference model Possible solutions Ad-hoc shortest widest path

indra
Download Presentation

ASWP – Ad-hoc Routing with Interference Consideration

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ASWP– Ad-hoc Routing with Interference Consideration June 28, 2005

  2. Scenarios • Deploy troops into field • Goals • QoS • Traffic classes, flow requirements • Scalable • Difficulty • Interference

  3. Outline • Problem description • Interference model • Possible solutions • Ad-hoc shortest widest path • ASWP problem • Proposed algorithm • Simulations • Conclusion

  4. Interference is critical • Wired networks • Independent links • Ad-hoc networks • Neighbor links interfere • Interference range > Transmission range • For simulations • Tx range = 500 m • Ix range = 1 km

  5. Interference Model • Conflict graph • G(X,A )  CG(A,I ) • Undirected graph • Violate Bellman’s Principle of Optimality • Clique Constraint • Node 13: path A (c) • Node 15: path A-D-E (c/3) • path B-C-D-E (c/2)

  6. Routing solutions • CG-based methods • Ideal solution • Clique constraint • Row constraint • Two-hops interference model • AQOR • MAC scheduling • SEEDEX, TDM/CDM • Connectivity only • DSR, AODV

  7. Outline • Problem description • Interference model • Possible solutions • Ad-hoc shortest widest path • ASWP problem • Proposed algorithm • Simulations • Conclusion

  8. Ad-Hoc Shortest Widest Path • Path metrics • Width • Length • Shortest widest path between (s,d ) • Want to find the widest path; • If more than one, take the shortest. • NP-complete

  9. ASWP Design • Separate scheduling and routing • Finding the widest path • Distributed algorithm • Clique computation • Path computation • Minimize overhead • Localized cliques

  10. ASWP Heuristic • Bellman approach • Key step • Compute path width for one-hop extension • Bottleneck clique • Unchanged • A maximal clique that the extending link belongs to • Can be done locally • K-shortest-path approach

  11. Outline • Problem description • Interference model • Possible solutions • Ad-hoc shortest widest path • ASWP problem • Proposed algorithm • Simulations • Conclusion

  12. Simulations – path width • 50-node network • Distant s/d pair • 7 hops away • X axis: load = average clique utilization • Y axis: path width

  13. Simulations – path width • 50-node network • Load = 0.32 • All pairs performance • X axis: distance between s/d pair • Y axis (upper): ratio of improved s/d pair • Y axis (lower): average improvement

  14. Simulations – admission ratio • 50-node network • Dynamic simulation • 5 s/d pairs • Randomly chosen • Given distance • Traffic model • Flow requests: 4Kb/s, 10,000 flow requests • Incoming rate: 0.32 flows per second • Duration: uniform distribution between 400 and 2800 seconds • Load = 0.32(400+2800)/24 = 2048 Kb/s = 2 Mb/s • Results: admission ratio (%)

  15. More on ASWP • Optimal path = shortest widest path • Complexity • Polynomial, but … • Running time (sec): • Optimal SWP necessary? • Wide path = long path • Long term behavior: bad

  16. Outline • Problem description • Interference model • Possible solutions • Ad-hoc shortest widest path • ASWP problem • Proposed algorithm • Simulations • Conclusion

  17. Conclusion • Overall goals • Bandwidth guaranteed path • Long-term admission ratio • Interference model • Conflict constraints • ASWP solution • Find shortest widest path • Distributed algorithm • Bellman-Ford architecture + k-shortest-path approach • A small k value is the good trade-off

More Related