1 / 23

Topology Management

Topology Management. Weihang Jiang Weili lin Vishvesh Sahasrabudhe. Outline. The function of “topology management” Different approaches for topology managements Several criteria of a “good” topology management “Problems” will be addressed now and then. The function of topology.

tiger-lancaster
Download Presentation

Topology Management

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. Topology Management Weihang Jiang Weili lin Vishvesh Sahasrabudhe

  2. Outline • The function of “topology management” • Different approaches for topology managements • Several criteria of a “good” topology management • “Problems” will be addressed now and then

  3. The function of topology • Scheduling of transmission, routing, broadcasting, spatial querying. • Main issue is power saving, and maintaining connected (is “connected” necessary?)

  4. Different Approaches Topology Management Power control Hierarchical K-connectivity 1-connectivity One - hop d-hops Non-deterministic (SPAN, Self-organization) Deterministic (TMPO)

  5. Several criteria of a “good” topology management • The most important criterion is power saving • Fewer cluster heads • Load balance • Average degree (power control) • Other criterion • Connectivity (SPAN, K-connectivity) • Algorithm convergence speed (self-organization) • Stability (fewer nodes changing their role: delay changes, how to decide the cycle?) • Mobility (always think about how to deal with the impact of movement, can we take advantage of it?) • Fault tolerant

  6. Fewer cluster heads • Method 1, select a lot of cluster heads to let all cluster heads connected, then withdraw unnecessary cluster heads to hosts • Method 2, select minimum dominating set, then add gateways/doorways to connect them • Method 3, using greedy algorithm, then on each phase, the cluster heads are connected • Method 4 ???

  7. Load balance • Method 1, Force long-term working cluster heads back to host nodes and sleep • Method 2, Select cluster heads basing on battery level (maybe partially)

  8. Power Control • Adjusting transmission range of nodes to achieve both connectivity and reduction of energy consumption

  9. 1-connectivity

  10. RA assignment problem • RA: determine RA such that the total cost of power is minimum • HRA:determine the minimum RA such that r-homogeneous assignment is connecting • KRA:determine the minimum RA such that is connected

  11. Problem? • Directional links B B A A

  12. Distance estimation • RSSi: radio signal strength(poor accuracy) • Toa: time of arrival

  13. Preferred K

  14. Mobility • Rely on volatile information(e.g. distance)

  15. K-connectivity • Motivation: fault tolerant

  16. Theoretical background

  17. Main problems

  18. Interesting problems • Relationship between k-connectivity and k minimum degree

  19. Power Management using Span • Requirements of power-saving coordination algorithm • Max idle nodes • Minimal delay in packet forwarding • Non-interference of original paths • No assumption of link-layer’s facilities for sleeping • Interoperate correctly with routing system

  20. Span Algorithm • A set of coordinators on for topology maintenance • Coordinator election based on connectivity and node power

  21. Span Algorithm • Local Coordinator election • Based on Coordinator eligibility • Two neighbors cannot reach each other – node becomes a coordinator • Announcement Contention resolved by back-off delay

  22. Span Algorithm • Delay Calculation based on connectivity and available power • Leads to efficient management of power and approx. maximum connectivity with minimum nodes

More Related