Subject: Re: [manet] how does ad hoc network do something?

From: Frank Dinies <[email-masked]>
Date: Wed, 24 Jul 2002 17:55:23 +0200

Hi Einar,

have you seen the approach from Fisheye-State-Routing ? It is a proactive 
algorithmen with maintains a global routing table. But it maintains the 
information in respect to the distance. To do this it sends periodically 
beacons to its neighbours only. Every neighbour accumulates this information 
and send the information in different update times. Information about nearer 
nodes much more often than information about nodes farer away. In this way 
this algorithmen scales pretty well with large networks and positionchanges 
not nescessarily triggers update information. 

On-demand protocols have the problem the route-prechaching is unsufficient for 
high mobility. Another point is that a route could even be absolute before a 
sender gets the route-information back.

unfortunalety there is no silver bullet for all kind of situations ;)

regards

frank     

> Hi Frank,
>
> >But keep in mind. Proactive algorithmens are best in enviroments with
> > rapid change and much participants. On-demand-ones roughly for the
> > contrary. For sensors that transmit from time to time small amounts of
> > data for example is an on-demand-one perfect.
>
> I was under the impression that it was the other way around, with proactive
> protocols performing worse in environments with rapid change, as the
> overhead with maintaining the (global) routing information would be
> prohibitive. Where as an on-demand protocol would perform better in this
> scenario?
>
> Or am I confused? :-)
>
> Cheers,
>
> Einar

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From: Frank Dinies <[email-masked]>
Date: Wed, 24 Jul 2002 17:55:23 +0200

Hi Einar,

regards

frank

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From: [email-masked]
Date: Sun, 28 Jul 2002 12:51:01 -0400 (EDT)

Hi Frank,

> unfortunalety there is no silver bullet for all kind of situations ;)

Yes, there is. Hybrid protocols adjust their behavior *dynamically* based
on the rate of changes (mobility) and the activity (rate of queries). They
optimize the total volume of control traffic, as to match the specific 
mobility/activity ratio.

Also, it is correct - higher rate of changes (higher mobility) and
lower activity favor on-demand (reactive) routing, ... and vice versa
for proactive protocols.

For more about this, see our publications on ZRP (http://wnl.ece.cornell.edu)
- but you're probably aware of this already.

Cheers,

Zygmunt.
===-==-====
~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-
Prof. Zygmunt J. Haas                    http://people.ece.cornell.edu/haas 
Wireless Networks Laboratory		 http://wnl.ece.cornell.edu
School of Electrical Engineering         
Cornell University			 tel: +1-607-255-3454
323 Frank Rhodes Hall			 fax: +1-607-255-9072
Ithaca, NY 14853			 e-mail: [email-masked]
U.S.A                             
	WNL web page: http://wnl.ece.cornell.edu
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From: [email-masked]
Date: Sun, 28 Jul 2002 12:51:01 -0400 (EDT)

Hi Frank,

Cheers,

Zygmunt.
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