D-07S-05: Difference between revisions

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==Problem Statement==
==Problem Statement==
* Early Warning Systems needs real-time communication (the reactive DSR protocol cannot achieve this)
*Which problem do you want to solve?
* using cheap COTS hardware (no or very limited access to the MAC layer, but it is fine to switch channels every x secs)
*To which domain of Computer Science does this problem relate to?
* 802.11b offers 3 non-overlapping channels, 802.11a even 12
*Why is the problem interesting? Why is it difficult?
* make use of these multiple channels by means of ("virtual") multiradio nodes like the WRAPBoards without excluding the common single radio nodes, i.e. utilise multiple radios (channels) whenever possible whithout requiring a node to have several radios



==Deliverables==
==Deliverables==
* Distributed channel assignment algorithm
*At the end of the project, what will you have delivered?
* based on a proactive routing protocol (allows world view)
*What does it mean that the project was successful?
* using unmodified standard 801.11 MAC (only interacting with the MAC by switching the channel of one the available interfaces from time to time)
* increase throughput (to retrieve data, e.g. MiniSeed) and decrease latency (for EWS) by using non-overlapping channels, i.e. a node can receive and transmit at the same time by having its to wifi interfaces at different channels


==Prior Art==
==Prior Art==
* several attempts to make use of the non-overlapping channels by proposing a different MAC layer (however, for COTS you usually do not have access to the MAC):
*Who are your competitors? What are they doing?
** [http://www.cs.berkeley.edu/~so/pubs/MSWiM_f05-mo.pdf Comparison of Multi-Channel MAC Protocols]
*How is your work different?
** [http://citeseer.ist.psu.edu/632582.html Multi-channel MAC with Dynamic Channel Selection for Ad Hoc Networks]
*List of publications related to your topic.
* Dissertation ''[http://scholar.lib.vt.edu/theses/available/etd-06262006-091312/unrestricted/ungheeLEEdissertation.pdf A Proactive Routing Protocol for Multi-Channel Wireless Ad-hoc Networks]'' by Unghee Lee (requires two radios at every node; one is used for control/routing information only and the other one for data/ack only)


==Key Ideas / Project Execution Plan ==
==Key Ideas / Project Execution Plan ==
* proactive protocols have a "world view" of the network. This is nice because routes to nodes do not have to be found out on demand prior to sending data (which is slow) (the routing protocol could also not only flood link state information but also other information every node with a certain hop distance (adjustable by TTL) should know like GPS coordinates of all nodes
*How will you approach the problem?
* the idea is to piggyback channel assignment information with the HELLO or TOPOLOGY CONTROL (TC) messages of http://olsr.org and to have a distributed channel assign algorithm taking into account joining/leaving/movement of nodes
*On which contributions of others do you depend on?
* both radios are used for data and control (routing) messages, no need to reserve one radio for control messages only
* 2 (or more) single radio nodes that are connected by an ethernet cable can form a "virtual multi-radio node



==Project Log==
==Project Log==
* getting an overview / reading papers
* What you have done so far? What You plan to do next?

==TODO==
* what kind of distributed channel assignment algorithms exist
* how do these work in case we have a world view (proactive protocol)

Revision as of 12:59, 21 June 2007

Using wireless mesh networks for Early Warning Systems

Assigned to: Jens Nachtigall

Advisor: Kai Köhne

Expected Submission: December 2007

Problem Statement

  • Early Warning Systems needs real-time communication (the reactive DSR protocol cannot achieve this)
  • using cheap COTS hardware (no or very limited access to the MAC layer, but it is fine to switch channels every x secs)
  • 802.11b offers 3 non-overlapping channels, 802.11a even 12
  • make use of these multiple channels by means of ("virtual") multiradio nodes like the WRAPBoards without excluding the common single radio nodes, i.e. utilise multiple radios (channels) whenever possible whithout requiring a node to have several radios


Deliverables

  • Distributed channel assignment algorithm
  • based on a proactive routing protocol (allows world view)
  • using unmodified standard 801.11 MAC (only interacting with the MAC by switching the channel of one the available interfaces from time to time)
  • increase throughput (to retrieve data, e.g. MiniSeed) and decrease latency (for EWS) by using non-overlapping channels, i.e. a node can receive and transmit at the same time by having its to wifi interfaces at different channels

Prior Art

Key Ideas / Project Execution Plan

  • proactive protocols have a "world view" of the network. This is nice because routes to nodes do not have to be found out on demand prior to sending data (which is slow) (the routing protocol could also not only flood link state information but also other information every node with a certain hop distance (adjustable by TTL) should know like GPS coordinates of all nodes
  • the idea is to piggyback channel assignment information with the HELLO or TOPOLOGY CONTROL (TC) messages of http://olsr.org and to have a distributed channel assign algorithm taking into account joining/leaving/movement of nodes
  • both radios are used for data and control (routing) messages, no need to reserve one radio for control messages only
  • 2 (or more) single radio nodes that are connected by an ethernet cable can form a "virtual multi-radio node


Project Log

  • getting an overview / reading papers

TODO

  • what kind of distributed channel assignment algorithms exist
  • how do these work in case we have a world view (proactive protocol)
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