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* Minimizing collisions (difficult: extended RTS/CTS? and using 802.11 non overlapping channels)
* Minimizing collisions (difficult: extended RTS/CTS? and using 802.11 non overlapping channels)


==Enigineering==
==Engineering==
Routingprotokolle aus Nachrichtensicht
Routingprotokolle aus Nachrichtensicht
Layer 3
Layer 3

Revision as of 14:25, 13 February 2006

Routing in Wireless Multi Hop Networks

Routing in wireless Networks Things to consider

  • Negative effects
    • self interference
  • Postive effects
    • Broadcast nature

Optimizing problems:

  • Minimizing transmissions (via Network Coding and ExOR)
  • Minimizing collisions (difficult: extended RTS/CTS? and using 802.11 non overlapping channels)

Engineering

Routingprotokolle aus Nachrichtensicht Layer 3 - Flooding - Multicast - Unicast

Layer 2 - Broadcast (lokal) - Multicast - Unicast

Die Idee ist, dass alle Routingprotokolle Nachrichten versenden müssen. In diese Nachrichten-Elemente steckt man dann nur noch den Payload.

Cruise Control

Need to added further project with dependencies to CruiseControl. E.g.:

  • click (i386, mips)
  • madwifi (-"-)

IvyCruise - dependencies with Cruise Control

Gateway

This is about the implementation of self-configuring internet access for BRN using Click mainly. (Need to explain design and implementation here (from the official gateway wiki site).)

Planned versions:

  • GatewayTester:
    • ICMP ping based
    • User traffic based
    • DNS query based
    • Challenge response based (with other mesh nodes)
  • Handling of TCP:
    • A GatewaySelector, which respects open TCP connections
    • A centralized "master" gateway (mesh gateways tunnel packets to)
    • Maybe handing TCP connections over to other mesh node?

ToDO

  • Recognize and handle NATed gateways
  • Is the GatewaySelector able to determine, if a mesh node is a gateway?
  • User feedback via LEDs

Further and dependent issues:

  • Connecting mesh nodes via ip tunnels
  • Connection mesh nodes via ethernet
  • Difficult to recognize, if an attached node is a client or a mesh node?

Known problems

  • Tried to implement an element by inheritance (a diamond), which is possible in C++. But it did not worked in Click. Maybe somebody has a working example. I tried virtual and so on, but it did not compile. In Click's configure method, you can only get an element. I wanted to convert an element of type A to type B without knowing the precise type of the given element.
    E
   / \
  /   \
 /     \
A       B
 \     /
  \   /
   \ /
    ?

This is not possible (my experience), since I don't know what ? is. I would need to cast the given element of type E to ? and then cast ? to A. You can use the delegation pattern to bypass the diamond.

WRAP and LEDs

Sentry5 - the netgear SoC (system on a chip)

Crpyto Acceleration in Linux

Embed Click into JiST

This is done via JNI.

Nsclick

+-----------+ | | | MAC | | | +-----------+

       |
       | wie FromHost ()
       +------------------> +-----------+
                            |           |
                            |   Click   |
               ToDevice     |           |
              +------------ +-----------+
              |                     ^
              |                     |
              |                     |
              V                     |
       +-------------+              |
       |             |              |
       |     PHY     +--------------+
       |             |   FromDevice
       +-------------+